Commentary - 1 John 5:18-21

Bird's-eye view

As John brings his short letter to a close, he does so with a resounding crescendo of assurance. But this is not the flimsy, sentimental assurance that is so common in modern evangelicalism. This is a robust, bone-deep certainty that is grounded in the absolute antithesis between light and darkness, between truth and lies, between God and the devil. John gives us three great certainties, three things "we know," that form the bedrock of our faith. He then concludes with a profound statement on the identity of Jesus Christ and a sharp, almost abrupt, command to steer clear of idols. The entire passage is designed to fortify the believer, to give him solid ground to stand on in a world that lies in the power of the evil one.

The structure is straightforward. John lays down three foundational certainties for the believer: our new nature in Christ protects us from the evil one (v. 18), our identity is in God while the world is in Satan's grip (v. 19), and our understanding of the true God is a gift from the Son (v. 20). This third "we know" culminates in one of the clearest declarations of Christ's deity in all of Scripture. The final verse (v. 21) is a punchy, pastoral command that flows directly from this high Christology. Because Jesus is the true God and eternal life, all other claimants to that title are nothing but idols, and we are to have nothing to do with them.

Outline

Context In 1 John

This final section of 1 John serves as the capstone to the entire letter. Throughout the epistle, John has been drawing sharp contrasts to combat the Gnostic-like heresies that were troubling the church. He has contrasted light and darkness, truth and lies, love for the brethren and hatred, Christ and antichrists. Now, he brings these themes to a powerful conclusion. The assurance he offers here is the answer to the uncertainty and false teaching he has been refuting. He has just discussed the "sin that leads to death" (v. 16), and now he provides the positive assurance that those truly born of God are kept from such apostasy. The declaration that "This is the true God and eternal life" (v. 20) is the final, definitive rebuttal to the heretics' diminished view of Jesus Christ. The closing warning against idols is a practical application of all that has come before: if you truly know the true God, then you will abandon all false ones.

Verse by Verse Commentary

18 We know that no one who has been born of God sins; but He who was begotten of God keeps him, and the evil one does not touch him.

John begins with the first of three foundational certainties: "We know." This isn't a guess, or a hope, or a pious wish. This is settled knowledge. And what is it that we know? That the one born of God does not sin. Now, we must handle this carefully. John has already told us in this very letter that if we say we have no sin, we deceive ourselves (1 John 1:8). So he cannot mean that a Christian never commits a single act of sin. Rather, he is speaking of the settled character and direction of a person's life. The one who is truly regenerate, born from above, does not make a practice of sin. Sin is the exception, not the rule. It is a foreign invader, not the governing principle of his life. The verb "sins" here is in the present tense, indicating a continuous, habitual action. The Christian does not live in sin.

The reason for this is given in the second clause. "He who was begotten of God keeps him." This refers to the Lord Jesus Christ, the only-begotten Son of God. Christ Himself is our guardian. The believer is not left to his own devices to fend off the devil. He is kept, protected, and preserved by the Son. This is our security. Our perseverance does not ultimately depend on the strength of our grip on Him, but on the strength of His grip on us. And because Christ keeps us, the conclusion follows: "the evil one does not touch him." This does not mean the believer is exempt from temptation or attack. The devil certainly prowls around like a roaring lion. But the phrase here means that the evil one cannot get a fatal grip on him. He cannot land a death blow. The believer is protected from the kind of sin that leads to death, the sin of apostasy, because he is kept by Christ Himself.

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

Here is the second "we know." This is a statement of position, of spiritual geography. John draws a stark, non-negotiable line. There are only two camps, two allegiances, two spiritual realities. First, "we are of God." Our origin, our identity, our very being is now sourced in God. We belong to His family, His kingdom. We are on His side. This is a declaration of our fundamental identity as Christians.

The contrast could not be more severe. "And that the whole world lies in the power of the evil one." The word for "lies in" can also be translated as "lies in the lap of." It pictures the entire world system, with its philosophies, its ambitions, its rebellions, and its false religions, as resting comfortably under the dominion of Satan. This is not a dualism where God and Satan are equal and opposite powers. God is sovereign over all, and the devil is a creature on a leash. But within God's sovereign decree, the world system, in its rebellion, has been given over to the influence and power of the prince of this world. There is no neutral ground. You are either "of God" or you are part of the world that "lies in the power of the evil one." This is why John's call is so urgent. You cannot flirt with the world and remain loyal to God.

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. This is the true God and eternal life.

This is the third and climactic "we know." This knowledge is the foundation of the other two. We know we are kept from sin and that we are of God because we know the Son of God. John affirms two critical truths about the Son's coming. First, "the Son of God has come." This is a direct shot at the Gnostic-like heretics who denied the incarnation. The eternal Son entered into human history. He was not a phantom or a temporary spiritual influence. He came.

Second, He "has given us understanding." True spiritual knowledge is not something we achieve; it is something we receive. It is a gift. The world by wisdom knew not God. But the Son has opened our minds and hearts "so that we may know Him who is true." This refers to God the Father. The only way to know the true God is through the revelation given by the Son. And this knowledge is not merely intellectual; it is relational. "And we are in Him who is true." We have union with the true God. How? John clarifies immediately: "in His Son Jesus Christ." Our union with the Father is through our union with the Son. We are in the Father because we are in the Son.

Then comes the thunderclap. "This is the true God and eternal life." To whom does the "This" refer? The closest and most natural antecedent is Jesus Christ. John is making one of the most unambiguous statements of Christ's deity in the entire New Testament. Jesus Christ is the true God. He is not a lesser emanation, not a created being, but the true God Himself. And He is "eternal life." Life is not a substance or a force; it is a Person. To have Jesus is to have life. This is the bedrock of our faith and the ground of all our assurance.

21 Little children, guard yourselves from idols.

After the soaring heights of the previous verse, this final command comes as a sharp, practical exhortation. John addresses his readers with pastoral affection: "Little children." And his final word to them is a warning: "guard yourselves from idols." Why this command here? Because it is the logical and necessary consequence of verse 20. If Jesus Christ is the true God, then anything and everything else that claims the devotion, allegiance, and worship that belong to Him alone is a false god, an idol.

An idol is not just a statue of wood or stone. An idol is anything that we substitute for the true God. It can be an idea, a philosophy, a political cause, a possession, a relationship, or even a religious tradition. Anything that takes the place of the true God in our hearts is an idol. The command to "guard yourselves" implies constant vigilance. Idolatry is the default setting of the fallen human heart. We are inveterate idol-makers. Therefore, we must be on guard. Knowing the true God in Jesus Christ is not just a matter of correct doctrine; it is a matter of exclusive worship. The letter ends here, leaving this crucial command ringing in our ears. Know the true God, and as a result, have nothing to do with the false ones.