Certainties For The Believer

December 14, 2025|Certainties For The Believer|1 John 5:18-21

JD Cutler

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This morning we finish not only John’s conclusion, but with that, our study of the epistle of 1st John.

Two weeks ago we began looking at John’s concluding remarks.

The whole section serves as both a reminder and summary of the confidence John wants to make sure that his readers have. If we had to distill down the emphasis of this concluding section, beginning in verse 13, and extending through verse 21, the word ‘know’ would be an obvious choice. 7 times in 9 verses John uses the word ‘know’, beginning with his purpose in writing, ‘so that we may know that we have eternal life’. He goes on to tells us that we know that God hears us, and since we know that he hears us, we know that we have what we have asked. Last week we looked at the ministry of intercession, which although John doesn’t use the word, contains the same emphasis. John wants us to know that we can pray for our brother or sister who is committing a sin, he wants us to know that God will answer those prayers, with the exception of someone who is committing sin that leads to death. He wants us to know that all wrongdoing is sin, but for believers, committing a sin is not a death sentence.

Today we will see him pick up on that thought while continuing his mission of reminding us of what we know for certain. Certainty is important, right?Certainty strengthens our resolve, emboldens us to act, protects us from wavering.

In Hebrews 11,  the author tells the abridged story of Noah, when he says…

English Standard Version Chapter 11

7 By faith Noah, being warned by God concerning events as yet unseen, in reverent fear constructed an ark for the saving of his household. By this he condemned the world and became an heir of the righteousness that comes by faith.

Noah was certain that what God said would come to pass, would come to pass and he his actions displayed his certainty in God even when the world would deem his undertaking as foolish.

If we are going to obey God and live lives that please him, certainty in Him and His word are central to our walk. The apostle, as we have already noted seems to be on a mission in his conclusion to give his readers certainties, statements that they can embrace, they can trust, and that they can build their lives on. As he continues, beginning in verse 18 we find three we know statements, each one a complete thought in the greek, but each one related to the one before it.

It is a rapid fire of a conclusion including three certainties that I want to share with you this morning by looking at three simple statements together.

Let’s read verses 18-21 together this morning and then look at who we are in Christ, what we are up against, and what we must be on guard against. 

1 John 5:18–21 ESV

¹⁸ We know that everyone who has been born of God does not keep on sinning, but he who was born of God protects him, and the evil one does not touch him. ¹⁹ We know that we are from God, and the whole world lies in the power of the evil one. ²⁰ And we know that the Son of God has come and has given us understanding, so that we may know him who is true; and we are in him who is true, in his Son Jesus Christ. He is the true God and eternal life. ²¹ Little children, keep yourselves from idols.

And with that, the apostle closes his letter to the churches. As we examine his words this morning, the first statement we are going to look at is…

I. WHO WE ARE IN CHRIST. 

We know that everyone who has been born of God does not keep on sinning.

This is both a repeated thought and a warning all in one.

First, this is not a new statement by John.

In chapter 3 he said…1 John 3:9 “9 No one born of God makes a practice of sinning, for God’s seed abides in him; and he cannot keep on sinning, because he has been born of God.”

He has also said…if we walk in the light, as he is in the light, we have fellowship with one another, and the blood of Jesus his Son cleanses us from all sin 

⁶ whoever says he abides in him ought to walk in the same way in which he walked.

²⁹ If you know that he is righteous, you may be sure that everyone who practices righteousness has been born of him. 

³ And everyone who thus hopes in him purifies himself as he is pure.

⁶ No one who abides in him keeps on sinning; no one who keeps on sinning has either seen him or known him.

²⁴ Whoever keeps his commandments abides in God, and God in him

Whether we are talking about walking in the light, walking in the same way in which he walked, practicing righteousness, purifying ourselves, abiding in him, we are talking about a radical departure from who we were before Christ.

Summed up in ‘no one born of God makes a practice of sinning’, or ‘no one who abides in him keeps on sinning.’

As we said when we studied those particular verses, the key words to understand, in order to grasp what John is saying is in chapter 3 and in chapter 5 are ‘make a practice’ and ‘keep on’ in regards to sinning. We are not talking about individual sins, we are not talking about the believer’s struggle to live pure and to forsake sin, we are talking about ongoing, persistent, unrepentant sin. John says here in chapter 5 the same thing he has said before, the life of one who has been born of God will not be characterized by habitual, unrepentant sin. It can’t be, because John says, God’s seed abides in Him, his nature has changed, he is a new creation in Christ. 

We know that, John says.

The idea of ‘we know’ is the idea that ‘it is well known’ or we ‘all understand this’. John can say that confidently, because if they did not know it when his letter, began they know it now. 

This new trajectory of our life is evidence that we have been born of God, or born again, as Jesus says in his meeting with Nicodemus. There Jesus tells Nicodemus that one must be born of the Spirit, to see the Kingdom of God and to enter the kingdom of God. There has to be a supernatural work of the Spirit in an individual’s life if they are going to experience eternal life.

How do we know that we have eternal life?

As we have seen, this has been the whole purpose of John’s letter. Jesus describes this kind of new life, as someone who has come into the light “so that it may be clearly seen that his works have been carried out in God.” A statement that John has expounded on throughout his letter and here at the end restates, everyone who has been born of God does not keep on sinning.

You can see how this is a repeated thought, but you may ask, ‘how is it a warning’?

Look back at verse 17. 1 John 5:17 “17 All wrongdoing is sin, but there is sin that does not lead to death.”

John has just spent time differentiating between sin that leads to death and sin that does not lead to death. He has helped us see our responsibility to pray for our brothers or sisters committing sin through the ministry of intercession. But what he does not want us to misunderstand is that while a brother or sister may commit sin, while they may stumble, they will not continue in sin. It will not be ongoing and habitual. I think he also doesn’t want to give us a license to sin. He does not want us to have an excuse for little sins, or sins that we might say do not lead to death. He wants us to truly understand that all sin is unrighteousness and it has no place among the life of a believer.

Sin is serious and even though it is present in our lives after our new birth, it is not something that fits with who we are any longer. It is no longer consistent with our nature, but rather it is an unwelcome presence in our lives. One that we fight against, one that we detest even its presence in our life. 

Sin is serious and even though it is present in our lives after our new birth, it is not something that fits with who we are any longer.

John wants us to understand who we are in Christ; we are born of God, we are children of God through salvation in Christ, through the working of the Holy Spirit, because of the will of the Father and the evidence of that is a new relationship with sin.

But he doesn’t stop there, he wants us to know that not only do we have a new nature that is incompatible with keeping on sinning, but we are protected, or kept. 

By who?

Let’s look at the statement John makes in verse 18 a little closer.

everyone who has been born of God- John uses the perfect passive tense speaking of all those who God has once for all brought to live in Christ. All those who have been individually born of God, do not keep on sinning.

But he who was born of God- Here John talks about a singular individual, and when he says he who was born of God, although it is the same greek word, he uses the aorist tense, which is an action without regard for past, present, or future time. We really don’t have an English equivalent for this tense.

We can read this in a variety of ways linguistically, but there are really only two that are consistent with the rest of scripture theologically.

One, that John is referring to Jesus as the one who protects the Christian, or two, God is the one who protects the Christian.

Either way, the emphasis is on the christian being divinely, supernaturally kept or protected.

Protected from who? The evil one.

How? The evil one does not touch him.

The word John uses is an interesting one. It doesn’t mean a momentary touch as much as it does taking hold of something. Jesus uses it when he tells Mary not to cling to him in his post resurrection encounter with him. I think John is saying that we are protected in Christ from the evil one taking hold of us. Yes he may shoot flaming darts at us (Ephesians 6:16), God may even give him permission to touch our possessions or our health, as he did Job, but just like there, God does not allow him to touch Job’s life, to do any permanent damage to him. Another encouragement is that satan is not able to grab ahold of us and shift us from our position in Christ. He cannot separate us from our Lord, he does not have the power to overcome us in that way, indeed, John has told us we overcome him through Christ.

What an encouragement! The great enemy of humanity cannot lay ahold of those who belong to Christ.

The great enemy of humanity cannot lay ahold of those who belong to Christ.

This by the way is a great argument against the false idea that a believer can be possessed. Satan has no such power against the believer who is in Christ. We are no longer under his control. He may afflict us but he cannot take hold of us.

In the midst of the difficulties these first century believers are facing, John reminds them that in Christ they have been born again and since they have been born of God, they are protected against the evil one. They are secure.Believers have been born of God, they have been forgiven of their sins and freed from the bondage of sin and death, and they will one day experience the fulness of that identity when they stand before Christ and are transformed to be like he is.

But, we still are in a battle against our flesh, the world, and the enemy. Yet John wants us to understand, even though we are in a battle with the enemy, the war has already been won, we will not be overcome, we are ultimately victorious through Christ.

This is who we are in Christ. 

The second statement we are going to look at this morning is…

II. WHAT WE ARE UP AGAINST.

Having established our identity in Christ, John continues with another we know statement.

Verse 19 ¹⁹ We know that we are from God, and the whole world lies in the power of the evil one. 

Because we know that we have been born of God, because we have examined our lives in light of scripture, because we have confidence of who we are, we understand that we are from God.

We know- with absolute certaintyFrom God- both in the source of our life and in that we belong to him

This doesn’t just serve as a summary of what John has said so far, he is setting up an important contrast here.

1 John is full of these contrasts. Light and dark, truth and lies, life and death, love and hate, things of God and things of the world, practicing righteousness and practicing sinning, belief and rejection.Here he contrasts the people of God with the rest of the world. It has been well said that in a scriptural worldview that there are only two kinds of people. Those who are in Christ and those who are not.

John has already said much about the differences between these two kinds of people.

Those who are in Christ have fellowship with God and with other believers.

Those who walk in the light have forgiveness of sin.

Those who are in Christ have an advocate with the Father.

Those who are in Christ have been anointed by the Holy One.

Those who are in Christ are God’s children now.

Those who are in Christ have confidence before God.

Those who are in Christ have the Spirit of God.

Those who are in Christ have been born of God.

Those who are in Christ have eternal life.

Either by implication or by express statement, John has said that those who are not in Christ…do not have fellowship with God, they are still in their sin, they have no advocate with God, they do not have the anointing, they have no confidence before God, they are dead, and they are children of the devil. 

In chapter 4 John says those who do not confess Jesus Christ has come in the flesh are not from God, they are from the world.In chapter 3 John says we should not be surprised that the world hates us. Reminding us that Cain hated Abel because the righteousness of his brothers deeds exposed the wickedness of Cain’s deeds.

John has contrasted the world with the people of God many times throughout his letter, and now in his conclusion he emphatically states, that while we are from God, the whole world lies in the power of the evil one.

Don’t miss this. John wants us to have confidence and assurance that we know that we are from God. He is our source of life and we belong to him, the Bible says elsewhere it this way, that our citizenship is in heaven, from which we await the return of our savior, the Lord Jesus Christ. But he also wants us to understand that we are surrounded by enemies of the cross of Christ, as Paul says in the same Ephesians passage where he tells us our citizenship is in heaven.

Until Christ returns and transforms us and subjects all things to himself, we are in enemy territory. Why?

Because the whole world lies in the power of the evil one. Not only do we know with absolute certainty that we are from God, we know with absolute certainty that the rest of the world is in subjection to the evil one. John contrasts everything he has said about believers being in Christ by saying that the world is in the power of the evil one. In the same way we are energized, shaped, and held by being in Christ, the world is energized, shaped, and held by the great enemy.

Here is the reality John is emphasizing. Despite the existence of countless political, cultural, and social entities in this world, there are actually only two realms. Everything and everyone that is not in Christ lies in the power of the evil one. Therefore, as John noted earlier in this epistles, the whole whole systems is hostile to God and to believers. As long as Jesus tarries, we are in a very real, all encompassing spiritual battle.

Yes Jesus has decisively won the war, yes we will be ultimately victorious through Christ, but make no mistake, we should expect difficulties and attacks from the world from the moment we are born again until we stand face to face with our Lord and Savior Jesus Christ.

It really is as simple as one commentator put it, Either you are “of God” and separate from this evil world, or you are of the world and you lie in the arms of the evil one.

Remember the primary reason John is writing, these false teachers, these antichrists John has been warning about; not only does he want the churches to be equipped to discern who they are, but he wants them to know that their presences is to be expected. They need to be constantly on guard against the enemy and his schemes. What more would satan love than to disrupt the fellowship of the brethren, to muddy the water of truth, and to distort the proper worship of God’s people?

This is what we as believers are up against. The world is not neutral or objective, but is at war with God and those who belong to him.All of your Christian life is going to be a battle against a tireless enemy, behind enemy lines, who employs deception, temptation, confusion, and schemes as the prince of the power of the air, as ruler of this present darkness, and god of this world. 

What more would satan love than to disrupt the fellowship of the brethren, to muddy the water of truth, and to distort the proper worship of God’s people?

Do you know that?

Do you understand why John says love of the world shows that the love of the Father is not in us?

Do you understand why James says that friendship with the world is enmity with God, therefore whoever wishes to be a friend of the world makes himself an enemy of God?

There is no third option, there is no compromise, if you are a believer you are at odds with the world and if you are of the world, you are at odds with God. Therefore, we should expect that hostility and attack would be normative for our lives, not the exception.

We know who we are, we know what we are up against, the third and final statement we are going to look at this morning is…

III. WHAT WE MUST GUARD AGAINST.

We come now to John’s final thought as he wrote in the greek, beginning in verse 20.

²⁰ And we know that the Son of God has come and has given us understanding, so that we may know him who is true; and we are in him who is true, in his Son Jesus Christ. He is the true God and eternal life. ²¹ Little children, keep yourselves from idols.

He again starts with we know, we all understanding, we all have grasped, what?

That Christ has come.The reference is to the incarnation, that Jesus Christ, the eternal son of God has entered into his creation, not to destroy it but to save it. We know this, how?

Because, not only did he enter into his creation, he revealed both himself and the Father, he has given us understanding. First in teaching his disciples and then second in sending the spirit of truth to indwell his people. 

He has previously called this understanding the anointing by the Holy One by which we have all knowledge. In that passage about guarding against antichrist we said that John is not saying we know everything, immediately upon being born again, but that we know the foundational truth of the gospel, the Spirit has revealed it to us in bringing new life to us.John says it is by the work of the Holy Spirit in the new birth that we receive understanding of who Christ is. Previously he has said that we can know that we have the Spirit of God because every spirit that confesses that Jesus Christ has come in the flesh if from God. 

Why did Jesus come and why did he give us understanding? So that, we may know him who is true…

In other words the primary objective of the divine gift of understanding is to lead us into knowledge of God. John says that we may know, using the present tense to indicate an ongoing, personal, growing knowledge of God. The goal of the Christian life is not simply to amass understanding of Biblical doctrine, of right theology, it is to grow in our knowledge of who God is, thoroughly submitting ourselves more and more to Him as we understand Him more and more. 

John says it this way, that we may know him who is  true, and we are in him who is true, in his Son Jesus Christ. This is the true God and eternal life.

In the greek, grammatically, the ‘this is’ could refer to God the Father or Christ the Son.

Either way, we know from the rest of scripture, that the Father is God and the Son is God.

I do not think John’s point is to emphasize one or the other, but to point us to the fact that Christ’s coming has brought the ability for us to know the true God and to know eternal life. 

It is of interest to note that where John concludes his letter is related to how he began it. 1 John 1:1–2 “1 That which was from the beginning, which we have heard, which we have seen with our eyes, which we looked upon and have touched with our hands, concerning the word of life— 2 the life was made manifest, and we have seen it, and testify to it and proclaim to you the eternal life, which was with the Father and was made manifest to us—” There John describes Jesus as the word of life, that which was from the beginning, that which is eternal life, that which was with the Father in eternity past and was made manifest in the incarnation.

John begins his letter by proclaiming Jesus is the only way to fellowship with God and he concludes his letter by pointing to the fact that those who are in the true, who know the true God, are those who are in Christ.

We can see pretty easily how this statement fits within the context of John’s letter and if John would have stopped at verse 20, it would have been a perfect place to end, proclaiming that the word of life that was manifested, that he is the true son of the true God and the only way to experience eternal life. And yet, John doesn’t stop there.

He says, Little children, keep yourselves from idols.

This statement almost seems out of place. Indeed many commentators don’t seem to know what to do with it, but I think it is the perfect ending for this letter.

Let’s start by looking at what John says in verse 21 and then work our way back.

Little children- this of course is a popular expression throughout John that we have talked about a few times, it is a pastoral, fatherly, loving address from an elderly apostle to those whom he loves. He has repeatedly used this phrase prior to an important exhortation. 1 John 2:28 “28 And now, little children, abide in him…1 John 3:7 “7 Little children, let no one deceive you…1 John 3:18 “18 Little children, let us not love in word or talk but in deed and in truth.” 

Similarly, now he says, little children keep yourself from idols. In his last words, he issues one last loving exhortation.

All of you, keep yourself from idols. 

What is an idol?

I think we can immediately let ourselves off the hook because we do not bow to a carved image or have an altar in our home. And yes, John’s immediate audience was surrounded by pagan worship, they would encounter physical idols and idol worship in their day to day lives much more readily than we do. But that really doesn’t get to the heart of what John is warning his readers about.

We often think of idols only as images or representations of things, but the amplified bible reminds us that idols are much more than carved images.

Anything and everything that distracts from or substitutes the place God should occupy in your life. (Is an idol)

"Little children, keep yourselves from idols (false gods)—[from anything and everything that would occupy the place in your heart due to God, from any sort of substitute for Him that would take first place in your life]." (Amplified)

Anything and everything that distracts from or substitutes the place God should occupy in your life.

This is an especially powerful command. There is both a sense of urgency and of personal responsibility in the way John issues this command. The wording demands an immediate and thorough response.

Remember, that these churches were facing the threat of gnostic teaching, most likely the Cerinthian heresey that taught that Jesus was Joseph and Mary’s biological son and the Holy Spirit descended on him at his baptism and departed him on the cross, that he was just a man whom the spirit of the Christ rested on. This was a direct attack on the gospel message and one that had dangerous implications for the faithfulness of the church. John wasn’t just warning about pagan worship but anything that fell short of Him who is true, the true God and His Son Jesus Christ. 

The only physical representation of God that is acceptable to worship is the person Jesus Christ.

It’s not a far stretch to think as John set forth the genuine thing, the incorruptible truth, that his mind went to all the ways that people substitute things for Him. Elsewhere the Bible says that Christ is the radiance of the glory of God and the exact imprint of his nature.

Jesus himself is recorded in John’s gospel as saying to the apostle Philip, Whoever has seen me has seen the Father. How can you say, ‘Show us the Father’?

The only physical representation of God that is acceptable to worship is the person Jesus Christ.

Therefore, anything that distorts his personhood or diminishes his divinity results in a idolatry. If there is anything that takes God’s place in your life as the one who deserves supreme loyalty and worship is an idol, whether that is represented by a physical article or not.

Don’t miss the connection here. What the enemy cannot take from us, what he cannot damage or grab ahold of is our relationship with and identity in Him, we can distort through idolatry.

John Calvin said “The human heart is a perpetual idol factory.” That is to say, we do not have to set out to make idols, it is our natural tendency to elevate things in our lives until they take the place of worship in our hearts.

How do we know if we have traded the true thing for an idol?

One way we can examine ourselves in light of John’s warning here is to ask what are we regularly sacrificing to?

For the person who has made a career or a job an idol, they may sacrifice family time, or their integrity to get ahead.

For the student who has made an idol out of their GPA may sacrifice relationships or their integrity to make the grade.

For the performance driven families who sacrifice gathering with the saints to play another tournament or win another game.

An idol doesn’t have to be a bad thing, it could be a good thing, but when it becomes a god thing in your life you have an idol problem. What in your life is so important to you that you regularly sacrifice time, values, priorities, and resources to participate in?

What is John’s warning against idolatry for the believer? Keep yourself from idols. This is a different word than what John used when he said we are protected, but it has a similar meaning. There we are told that we are kept in the state we are in, we are protected, here John says to guard ourselves.

Be on guard against the idols that come from within as well as the ones that tempt us from without. Even more telling is John’s choice of words when he says keep yourself from- the idea of from is a separation. It seems John is saying for us to put some distance between ourselves and whatever the idols are in our life. We are not as strong as we think we are and as John has already said, there can be no fellowship with both God and idols. You cannot make any provision for an idol, it is an open door that will absolutely be taken advantage of. If you have struggled with something holding too high of a place in your life, you need to avoid that diligently.

How do we keep ourselves from idols, we cling to that which is true and genuine, our Lord and savior Jesus Christ. 

John concludes his letter by warning us to be on guard against accepting anything less than the genuine article and to actively separate ourselves from anything that robs God of our supreme allegiance and worship. Jesus Christ is the only “express image of God’s person” which is sanctioned, the only true visible manifestation of God. All other representations of God are forbidden as idols.

Thus the Epistle closes as it began with a high view of Christ and a call to hold on to the truth of the gospel.

As believers we have encountered the true God and should be satisfied fully and finally in Him.We are no longer of the world, even though we are in the world. We are surrounded by enemies, while simultaneously battling our old nature and the idol factory of our hearts. We are children of God, kept secure in Christ and protected from the evil one. We are empowered by the Spirit of God to battle sin and forsake all forms of idolatry.

As we close, I want to share with you some words from a commentary I encountered while studying for this message. It says, ‘In light of many recent surveys, which show that there is no discernible difference in morals or values between those claiming to be born again and the population at large, it is not out of line to ask, ´Do you know this? Is there a fundamental difference between your priorities and goals and those of your non-Christian neighbors? Are you living for God and His glory and kingdom, or do you just attend church services a little more often than the rest of the population?

To that I would add, are you living like you know that which is true, the real, the authentic, the very source of life?

Are you living your live with certainty as a believer, is it shaping your deeds and your days?

As we conclude John’s letter, may it be a tool in the hands of our living God to operate on our hearts and minds to expose error, encourage us in the truth, and to equip us in our fight against an ever vigilant enemy.

Let us pray. 

Father, remind us that belonging to you and being from you is inconsistent with  life of ongoing unrepentant sin. Thank you that we are safe in Christ and that Satan cannot grab ahold of us and pull us away from Christ. Protect us in the world that is under his power and empower us to be light and salt where you have placed us in the world. Thank you for the illumination of the spirit, by which we believe and trust that Jesus Christ is the true representation of the true God, and through whom we may have true eternal life. Strengthen us to separate ourselves from the idols that would tempt us and lead us away from you. In Jesus name. Amen