1 John 5:20 says that the Son of God has come and given believers the ability to know the true God, and that this knowing is found in his Son, Jesus Christ. John states that the true God and eternal life are the same reality, received through relationship with Jesus. The verse was written by the apostle John, traditionally identified as the author of the letter, and addressed to a community of Christian believers who needed assurance of what they already possessed.
We know that the Son of God has come, and has given us an understanding, that we 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.
1 John 5:20 (WEB)
What 1 John 5:20 Means
The verse begins with “We know,” a phrase John uses repeatedly in this letter. He is not hoping or guessing. He is describing settled confidence based on what God has already done. The Son of God “has come,” which points to the incarnation, the real arrival of God in human flesh in Jesus. Because of that arrival, John says, believers have “an understanding,” a mind enabled to grasp who God is.
The heart of the verse is the claim that we know “him who is true” and are “in him who is true,” both of which are tied to Jesus Christ. John is saying that knowing God and being united with God are inseparable. The closing statement, “This is the true God, and eternal life,” identifies Jesus as the true God and says that eternal life is found in him. The verse does not promise that believers will understand everything or never struggle with doubt. It affirms that real knowledge of God and life with him have been given through Christ.
The Context of 1 John 5:20
The letter of 1 John was written to strengthen believers facing false teaching, likely from people who had left the community and claimed a superior knowledge of God. John repeatedly tests claims about Jesus against the reality of his coming in the flesh, love for one another, and obedience. Verse 20 functions as a summary of the letter’s central confidence: real knowledge of God comes through the Son, not through a secret or superior insight.
The surrounding verses set the stage. Verse 19 speaks of a world lying under the power of the evil one, while verse 20 gives the contrast: believers know the one who is true. Verse 21 immediately follows with a warning to keep away from idols. Read in this setting, the verse is not abstract theology. It is a reminder that those who belong to Christ are called to hold fast to the true God rather than to counterfeit substitutes.
Key Phrases in 1 John 5:20
John 17:3
This is eternal life, that they should know you, the only true God, and him whom you sent, Jesus Christ.
(WEB)
Jesus himself defines eternal life as knowing the only true God and the one he sent. This connects closely with 1 John 5:20, showing that the letter’s teaching flows directly from the words of Christ and that knowing God through Jesus has always been the center of Christian faith.
1 John 4:15
Whoever confesses that Jesus is the Son of God, God remains in him, and he in God.
(WEB)
This verse affirms that whoever confesses Jesus as the Son of God lives in God and God in them. It echoes the same theme of mutual abiding found in 1 John 5:20, emphasizing that a true confession of Christ leads into a living relationship with God.
A Short Prayer From 1 John 5:20
Father, thank you that your Son has come and opened my mind to know you. I confess that I often feel unsure of myself and tempted to look for security elsewhere. Help me rest in the truth that I am in Jesus Christ, the one who is true. Let my life be shaped by the eternal life you have given me, and keep my heart from anything that would take your place. Amen.
