BIBLE VERSE STUDY
John 17:3 — Eternal Life as Knowing the True God
Jesus defines eternal life not as duration but as relational knowledge of the only true God and the sent Son, Jesus Christ.
Scripture
3And this is life eternal, that they should know thee the only true God, and him whom thou didst send, even Jesus Christ.
What this passage means
Verse 3 sits inside Jesus' prayer to the Father (John 17:1–2) and supplies the content of what was just requested: that the Son would give eternal life to all whom the Father has given him. The verse is best read as Jesus' own definition of the "eternal life" named in verse 2. Eternal life is not first of all a length of time but a quality of relationship — knowing (Greek γινώσκωσιν) the only true God and Jesus Christ whom he sent.
The construction "that they should know" uses ἵνα (G2443) with the subjunctive, marking the clause as purpose or result. Knowing is not bare intellectual acknowledgment; in John's usage the verb γινώσκω (G1097) carries relational weight, overlapping with the Hebrew sense of intimate, covenantal knowledge. To "know" the Father and the Son is to be in living communion with them, animated by the very words the Son has spoken (cf. verse 8).
The verse makes two christological claims at once. First, it identifies the Father as "the only true God" (τὸν μόνον ἀληθινὸν Θεόν — G3441, G0228, G2316), affirming monotheistic distinction. Second, it places Jesus Christ, the one sent (ἀπέστειλας, G0649), as the equally proper object of that knowing — the one alongside the Father whom eternal life consists in knowing. Eternal life, then, is the believer's relational knowledge of Father and Son together.
Context
John 17 is presented as Jesus' prayer to the Father after the Last Supper discourse. Verses 1–2 frame the request: the hour has come, the Father has given the Son authority over all flesh, and the Son's task is to give eternal life to those given to him. Verse 3 then opens the body of the prayer by defining what that eternal life is.
The rest of the chapter develops themes that grow out of this definition: the Son has manifested the Father's name to those given him (6), the disciples have received the Father's words and believed that the Son was sent (7–8), unity among believers is repeatedly grounded in the mutual indwelling of Father and Son (21–23), and the prayer closes with the request that those given to the Son behold his glory (24). Verse 3 thus functions as the theological key for the whole prayer.
Key words in the original
- G0166 αἰώνιος (G0166), supplied by the Greek lemma αἰώνιος, modifies ζωή (G2222) and means "age-long" or "eternal." In John 17:3 the adjective does not by itself settle whether eternal life is a duration or a quality; the verse's own definition — knowing God — shows that quantity and relationship are fused together.
- G1097 γινώσκω (G1097), appearing in the subjunctive γινώσκωσιν, is John's characteristic verb for the knowing that issues from revelation and issues into fellowship. The form here is durative-habitual, suggesting continuing, growing acquaintance rather than a single moment of information.
- G0228 ἀληθινός (G0228), supplied by the lemma ἀληθινός, modifies "God" (Θεόν, G2316) and contrasts "the true" with what is counterfeit, shadowy, or merely nominal. John elsewhere opposes ἀληθινός to false gods and to mere earthly substitutes, so that "the only true God" is a polemical as well as an affirmative designation.
Related verses
- 1 John 5:20 1 John 5:20 echoes John 17:3 almost verbatim: knowing "him that is true" and being "in his Son Jesus Christ" who "is the true God, and eternal life." The two passages mutually clarify that the relational knowledge of 17:3 is also union with the Son, and that the Son shares the Father's designation as true God.
- 1 John 5:11 1 John 5:11 grounds the definition of John 17:3: the witness God has given is that eternal life is located "in his Son." Knowing God and knowing the Son cannot be separated, because the life itself resides in the Son.
- Jeremiah 9:24 Jeremiah 9:24 anticipates the structure of John 17:3: the one who glories is to glory in 'understanding, and knowing' that the Lord is. John recasts covenant 'knowing' as directed jointly to the Father and to the sent Son, taking up the Old Testament theme of knowing YHWH and deepening it christologically.
Common questions
Does John 17:3 deny that Jesus is God?
The verse does not deny Christ's deity. It distinguishes the Father as "the only true God" and then places Jesus Christ as the one alongside the Father whom believers are to know. 1 John 5:20, which closely echoes this verse, goes further and explicitly calls the Son "the true God, and eternal life." John 17:3 is therefore read as distinguishing persons within the one Godhead rather than ranking the Son below the Father.
Is "eternal life" in this verse a duration or a relationship?
Verse 3's own definition — knowing the Father and the Son — shows that the two senses are fused. The adjective αἰώνιος (G0166) marks the life as belonging to the age to come and unending, but the content of that life is relational knowledge, so duration and quality are not opposed here. Eternal life begins in the present knowing of the Son and continues unbroken.
What kind of "knowing" does γινώσκω (G1097) describe here?
It is not neutral information. In John's usage γινώσκω denotes the knowing that comes through revelation and results in fellowship. The present subjunctive form γινώσκωσιν suggests ongoing, growing acquaintance with the Father and the Son, grounded in the words the Son has received from the Father (cf. verse 8).