First 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 eternal life itself. The verse is a statement of confidence, not a request: the writer is reminding his readers of what they already have in Christ. It was written by the apostle John, traditionally identified as the author of the Gospel and the three letters that bear his name, and it was addressed to a community of Christians who needed assurance of their standing with God.
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 often in this letter. He wants his readers to be certain, not merely hopeful. The Son of God “has come,” which points to the incarnation: God entered human history in Jesus. Because of that coming, believers have been given “an understanding,” a settled capacity to recognize and rest in the one who is true. John is describing a knowledge that comes as a gift, not one that people reach by their own effort.
The verse then says that we are “in him who is true, in his Son Jesus Christ.” Being “in” Christ is a recurring picture in John’s writings: a close, living union, not just agreement with a set of ideas. The final sentence identifies Jesus Christ as “the true God, and eternal life.” Some readers take “this” as pointing to Jesus and others to the true God, but either way the sentence ties God, Christ and eternal life tightly together. The verse does not promise a life free from trouble. It promises a relationship with the true God that already begins now.
The Context of 1 John 5:20
First John was written to Christians facing pressure from false teachers who denied that Jesus had truly come in the flesh and who claimed special knowledge of God. Against that background, John repeatedly tests claims by asking whether they match the truth about Jesus and whether they produce love and obedience. The “we know” statements in the letter are meant to give believers a firm footing when others are confusing them.
The verses just before this one speak of the evil one and the whole world lying under his power, while God’s children are kept safe and belong to God. Verse 21 then warns the readers to keep themselves from idols. Read in that setting, verse 20 is the anchor: because the Son has come and given true understanding, believers can recognize the real God and reject every rival claim to be him.
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 defines eternal life as knowing the only true God and the one he sent. This verse in the Gospel lies behind the thought of 1 John 5:20 and shows that knowing God and having eternal life belong together.
1 John 5:13
These things I have written to you who believe in the name of the Son of God, that you may know that you have eternal life, and that you may continue to believe in the name of the Son of God.
(WEB)
Just before the verse in focus, John states that he writes so that believers may know they have eternal life. It shows the purpose of the letter and reinforces the note of assurance that runs through 1 John 5:20.
A Short Prayer From 1 John 5:20
Lord, you have come to us in your Son, Jesus Christ, and you have given us the understanding to know you who are true. Thank you that this knowing is not something I have to earn or manufacture. Quiet my fears when I doubt where I stand, and remind me that I am in you through him. Let your life take root in me today, so that my choices and my words reflect the truth I have been given. Amen.
