1 John 5:18

Each of the first three verses opens with “we know”. The verb is eídō, which properly means to see, and here it is used for knowing something settled and sure, a conviction that rests on the new birth and on what God has shown us. That confidence runs through the whole letter. John has just written so that those who believe on the name of the Son of God may know that they have eternal life (1 John 5:9–13), and earlier he gave keeping God’s commandments as the way we know that we know him (1 John 2:3–4). He has also spoken of the victory that overcomes the world, which is our faith (1 John 5:4), and of the confidence we have that God hears us when we ask according to his will (1 John 5:14–17).

The letter was written late in the first century, probably from Ephesus, to churches troubled by false teachers. They denied that Jesus Christ had truly come in the flesh, and they claimed a special knowledge of God while living as they pleased (1 John 2:18–23, 1 John 4:1–6). John answers them with what every believer knows: a life changed by God, a Saviour who really came, and a true God who can be known.

John is describing the settled course of a life that God has brought to birth, and whoever is born of God does not go on living in sin as a way of life. The verb for “sinneth”, hamartánō, means to miss the mark, to err or to sin, and it stands here in the present tense, which describes ongoing, habitual action. A child of God still stumbles. John himself wrote, “If we say that we have no sin, we deceive ourselves, and the truth is not in us,” and in the same breath promised that God forgives the sins we confess (1 John 1:8–9). What the new birth ends is a life given over to sin and lived in it without repentance, because the new nature God gives is set against sin’s rule.

“Born” and “begotten” in this verse translate the same verb, gennáō, to beget or to be born. Here it means the new life God himself gives, which makes a person his child and is wholly his work. Jesus told Nicodemus, “Ye must be born again” (John 3:3–7), and John’s Gospel says that those who received Christ were born “of God” (John 1:12–13). This birth moves a person from darkness into light (1 John 2:9–11). John has already set the children of God beside the children of the devil and shown that each is known by how he lives (1 John 3:7–10). Paul teaches the same when he says that believers have died to sin and are alive to God in Christ Jesus, and are to yield themselves to God (Romans 6:1–14). Christ’s death and resurrection broke sin’s dominion, and that is what makes the new life possible.

“He that is begotten of God keepeth himself.” The verb tēréō means to guard, to preserve, or to watch over carefully, and heautoû is the plain reflexive “himself”. The one born of God watches over his own life. He stays alert, obeys God’s commands and abides in Christ, and he does it by the strength God gives through the Holy Spirit, who enables him to walk in the Spirit (Galatians 5:16). Paul puts the two sides together: “work out your own salvation with fear and trembling. For it is God which worketh in you” (Philippians 2:12–13). God is the great Keeper of his people, and Jude gives glory to the one who is able to keep us from falling (Jude 1:24).

The promise is that the child of God is beyond the reach of Satan’s grip, safe from being claimed or destroyed by him. “That wicked one” translates ponērós, a word for what is evil and hurtful, and with the article it names Satan, the enemy of God and of his people. The verb “toucheth”, háptomai, means to touch with firm contact, and Strong’s gives its root sense as “to attach oneself to”. Joined to the plain negative ou, “not”, it tells us that the evil one is unable to fasten on the one God has begotten.

Believers still meet temptation, suffering and attacks from the enemy, which is why Paul tells us to put on the whole armour of God (Ephesians 6:10–18). What the evil one is unable to do is cut them off from God or take them out of Christ’s keeping. Jesus said of his sheep, “neither shall any man pluck them out of my hand” (John 10:28–29). This safety rests on Christ’s victory at the cross, where he disarmed principalities and powers (Colossians 2:15), and on the Father, who has delivered us from the power of darkness into the kingdom of his dear Son (Colossians 1:13).

“We are of God” (ek Theou, “out of God”) means that our life comes from him. Born of God, we take our nature, our life and our loyalty from him, and we belong to his family as his children, partakers of the divine nature (2 Peter 1:4). Jesus told his disciples, “ye are not of the world, but I have chosen you out of the world” (John 15:19).

“The whole world”, ho holos kosmos, here means humanity organized against God, with its values, its ways and the spiritual powers behind them. John’s subject is the fallen human order, people and their ways set against their Maker. That world “lieth”, keîmai, a verb meaning to lie or to be laid. It lies “in wickedness”, and the word is ponērós again, the same word used in verse 18 for “that wicked one”. In John’s writings it often points to the evil one himself, so the verse pictures the whole world lying in his power.

Scripture names him the prince of the power of the air, at work in the children of disobedience (Ephesians 2:2), and the god of this world, who blinds the minds of unbelievers (2 Corinthians 4:4). Christ gave himself to deliver us from this present evil world (Galatians 1:4). John has already written to young men who have overcome the wicked one (1 John 2:13–14), and he has told his readers, “greater is he that is in you, than he that is in the world” (1 John 4:4).

“The Son of God is come.” The verb hēkō means to arrive and be present, and it speaks of the incarnation: the Son of God really came into the world as a man, as John insists against those who denied it. The Word who was God and made all things (John 1:1–4) was made flesh and dwelt among us (John 1:14).

He came with a purpose, and he “hath given us an understanding”. The word diánoia means the mind, the power of deep thought, or the mind’s disposition. Here it is the insight Christ gives so that we can grasp divine truth, above all who God is and who his Son is, and we receive it as his gift. In Jesus the Father is fully shown (John 14:9), and through his coming, his death and resurrection and the sending of the Holy Spirit he has opened our eyes to know God.

“That we may know him that is true.” The verb here is ginṓskō, to know, come to know, perceive or understand, and “him that is true” is God the Father. This knowing is given by the Son and leads into fellowship, for the next words say that we are in him. Jesus prayed, “And this is life eternal, that they might know thee the only true God, and Jesus Christ, whom thou hast sent” (John 17:3). John’s word for “true”, alēthinós, comes from alēthēs, “truthful”, and describes what is genuine and real, set over against what is false or counterfeit. The God we know is the real God, which is why the warning about idols follows.

“And we are in him that is true, even in his Son Jesus Christ.” We are in the true God by being in his Son, and so union with the Father and union with the Son belong together. Christ is the one through whom we come, as he said: “I am the way, the truth, and the life: no man cometh unto the Father, but by me” (John 14:6).

“Little children” is tekníon, a diminutive of teknon, “child”. John uses it through this letter for those he loves as his own children in the faith (1 John 2:12, 1 John 2:28), and it gives his last command the tone of a father’s loving warning.

“Keep” here is phylássō, to watch, to be on guard, to preserve, a word for guarding against a danger from outside. It shares the English word “keep” with verse 18, where the verb was tēréō. “Yourselves” is again the plain reflexive heautoû, and the command is given to the believers themselves, who are to guard their own hearts as those who abide in Christ (John 15:4) and walk as he walked (1 John 2:6).

“Idols” is eídōlon, from eidos, “form” or “appearance”: an image made for worship, a heathen god, an idol. John’s readers lived in a Roman world full of pagan gods, emperor worship and mystery cults, where bowing to statues was the custom all around them. His warning covers those statues, and it also reaches whatever takes the place of the true God in our trust, love and loyalty, including false teaching about Christ and the world’s philosophies. Having just named Jesus Christ “the true God”, John warns against every false one.

This is the oldest command in Scripture about worship: “Thou shalt have no other gods before me” (Exodus 20:3). Israel turned again and again to other gods, and mankind “worshipped and served the creature more than the Creator” (Romans 1:25). Paul tells believers to flee from idolatry (1 Corinthians 10:14) and counts covetousness as idolatry (Colossians 3:5). Today an idol is seldom a carved image. It can be money, a career, a relationship, technology, entertainment, self-image, a political cause, or a religious habit that has become an end in itself.

Christ himself lived in perfect devotion to the Father. He said, “I and my Father are one” (John 10:30), and he came down from heaven to do the will of the one who sent him (John 6:38). He is the image of the invisible God (Colossians 1:15), the one true image against all the images people make, and the Spirit who lives in us enables us to live as God wills (Romans 8:4).

These verses give us certainty about where we stand. God has given us new birth, he keeps us from the evil one’s grip, and he has made us his own in a world that lies in that one’s power. His Son has come and opened our minds to know him, so that we are in the true God by being in Jesus Christ, who is himself the true God and eternal life. Here God shows himself as the real and living God, who comes to his people in his Son and holds them fast, and beside him every idol is counterfeit. John’s last word to his little children comes from that same love, a father’s warning to guard what God has given.