Where it fits

First John is the twenty-third book of the New Testament, with five chapters. The letter doesn't name its author, but its language is so close to the Gospel of John that it has traditionally been ascribed to the apostle John, writing to churches he knew well, probably around Ephesus late in the first century. The writer speaks as an eyewitness who heard, saw, and touched the Word of life (1:1). Read straight through, it takes about 15 minutes.

Who, to whom, and why

The church was shaken. Some members had left the community (2:19). They were denying that Jesus is the Christ who came in the flesh (2:22; 4:2–3), and some seemed to claim fellowship with God while ignoring how they lived (1:6; 2:4). Those who stayed were left wondering whether they really belonged to God. John writes to reassure them, and he says he writes so that they may know they have eternal life (5:13).

John doesn't follow a strict outline. He circles back, like a spiral, to three themes. The first is truth: Jesus is the Son of God who came in the flesh, and believers must hold to that (2:22–23; 4:2–3; 5:1). The second is obedience: those who know God keep his commands and walk in the light as Jesus did (1:5–7; 2:3–6). The third is love: God is love, and anyone who claims to love God while hating a brother or sister is a liar (4:7–21). The letter ends with a warning to keep away from idols (5:21).

Three ideas to hold on to

1. God is light and God is love. John says God is light, with no darkness in him (1:5), and that God is love (4:8, 16). The two belong together: to know God is to walk in the light and to love.
2. Forgiveness is real, and it starts with honesty. If we say we have no sin, we deceive ourselves, but if we confess our sins, God is faithful and righteous to forgive us (1:8–9).
3. You can know. Eternal life is in the Son, and believers can be sure they have it (5:11–13). John gives three tests to help: belief in Jesus, obedience, and love.

Passages people ask about

• 1 John 1:5–2:2. Walking in the light, confessing sins, and Jesus as the one who speaks to the Father on our behalf.
• 1 John 3:4–10. Those born of God don't keep on sinning. Christians read this alongside 1:8–10, and most understand John to mean a settled practice of sin, not that believers never sin.
• 1 John 4:1–6. Test the spirits. The test is what a teacher says about Jesus.
• 1 John 4:7–21. The great passage on love, rooted in God's love for us in sending his Son (4:9–10).
• 1 John 5:16–17. The sin that leads to death. John doesn't say what he means, and Christians have offered many answers. It is one of the hardest verses in the letter.

How it points to Jesus

John opens by saying that the eternal life that was with the Father was made visible in Jesus (1:2). He is the Son of God who came in the flesh (4:2), the atoning sacrifice for our sins and for the whole world (2:2; 4:10), the advocate who pleads for us (2:1), and the one in whom we have life (5:11–12). John says the way to know love is to look at the cross: love is “not that we loved God, but that he loved us” (4:10).

A common misunderstanding

“God is love” (4:8) is sometimes taken to mean that God accepts everything and judges nothing. John won't allow that. In the same letter, love is defined by what God did in sending his Son to be the sacrifice for our sins (4:9–10), and love for God is shown by keeping his commands (5:3). John's love is warm, but it has a spine. It tells the truth, and it costs something.