Passage
John 17.3
Book: John · NASB95
Verse
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"This is eternal life, that they may know You, the only true God, and Jesus Christ whom You have sent." (John 17:3, NASB95)
Immediate context (±2 verses)
NASB95 (NASB95)
"1. Jesus spoke these things; and lifting up His eyes to heaven, He said, 'Father, the hour has come; glorify Your Son, that the Son may glorify You, 2. even as You gave Him authority over all flesh, that to all whom You have given Him, He may give eternal life.'"
"3. This is eternal life, that they may know You, the only true God, and Jesus Christ whom You have sent."
"4. I glorified You on the earth, having accomplished the work which You have given Me to do. 5. Now, Father, glorify Me together with Yourself, with the glory which I had with You before the world was." (John 17:1-5, NASB95)
Setting
- Speaker: Jesus, in the High Priestly Prayer (John 17).
- Audience: the Father, with the disciples within earshot.
- Location: Jerusalem, the upper room or en route to Gethsemane (cf. John 17.5).
- Time period: Passover eve, c. AD 30, the night before the crucifixion.
Theological reading
The verse is the only definitional statement of "eternal life" in Jesus's own words, and one of the most precisely-engineered statements about both God's identity and Christ's relation to the Father. Two claims:
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Eternal life defined. Hautē estin hē aiōnios zōē, "this is eternal life." Eternal life is not primarily a duration (although duration is included) but a relationship: knowing the true God + Jesus Christ. The relational definition transforms everything else about the doctrine. See G2222 - zoe for the full lexicon treatment.
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The relational content, knowing. Hina ginōskōsi se, "that they may know You." The verb is ginōskō, experiential, relational, intimate knowledge. Not propositional acquaintance ("knowing about") but personal relational knowing ("knowing personally"). Eternal life = knowing the Father + the Son.
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The dual object of knowing, Father and Son. Ton monon alēthinon theon kai hon apesteilas Iēsoun Christon, "You, the only true God, and Jesus Christ whom You have sent." Both the Father and Jesus Christ are the relational object of saving knowledge.
The Christological tension, "the only true God"
The verse generates a major Christological dispute. The phrase ton monon alēthinon theon, "the only true God", refers to the Father. The unitarian / Watchtower argument: this verse explicitly distinguishes the Father (= the only true God) from Jesus (= someone other than the only true God). Therefore Jesus is not God; Jesus is "the one whom the only true God sent."
The orthodox response (multiple converging arguments):
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The verse identifies the Father specifically as the one whose unique identity excludes idols and false gods, not Christ. The phrase "only true God" is contrasted with idolatry (compare 1 Thessalonians 1:9, turning from "idols to serve a living and true God") and with false claimants, not with Jesus the Son. Jesus is not identifying the Father over-against Himself but the one God (Father, in immediate context; Son included by extension throughout John's Gospel) over-against the false gods.
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The same Gospel's broader Christology. The Gospel that contains John 17:3 also contains John 1.1 (theos ēn ho logos), John 8.58 (egō eimi), John 20.28 (ho theos mou), John 1.18 (monogenēs theos). Reading John 17:3 to deny Christ's deity contradicts the same Gospel's other claims. The unitarian reading creates an internal contradiction within John alone.
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"To know Jesus Christ" is paired with knowing the only true God. The construction kai hon apesteilas Iēsoun Christon, "and Jesus Christ whom You have sent", places knowing-Jesus as the same kind of saving relational knowledge as knowing-the-Father. If Jesus were merely a created messenger, knowing Him would not be salvific in the same sense as knowing-God. The structure presupposes Jesus's deity.
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The resolution in Trinitarian Christology. The verse names the Father as "the only true God" because the Son is included in the Father's deity. The Father is not a separate God; He is the one God, and the Son shares that one being. So "knowing the only true God" includes knowing the Son who is one in essence with the Father (Bauckham's "divine identity Christology" again).
Patristic / scholarly note
The patristic tradition addresses John 17:3 against Arian readings. Athanasius (Discourses Against the Arians III.9, c. AD 358) explicitly defends the verse: "the one true God is the Father, but the Son is with the Father in this one true God-ness; the verse does not divide Father from Son but unites them in one divine being." Cyril of Alexandria (Commentary on John, Book 11) develops the same argument.
Augustine (Tractates on John 105, c. AD 414): "the verse identifies the Father as the only true God in distinction from idols, not in distinction from the Son. The Son is included in the Father's deity, sharing the same true divine essence."
Modern conservative: D. A. Carson (The Gospel According to John PNTC, 1991); Andreas Köstenberger (John BECNT, 2004); Murray Harris (Jesus as God, 1992); Larry Hurtado (Lord Jesus Christ, 2003), all defend the orthodox-Trinitarian reading. The verse is not Arianism's smoking gun; it is consistent with Trinitarian-monotheism when read in context.
Eternal life, relational, not merely durational
The verse transforms popular misconceptions of "eternal life":
- Not just "going to heaven when you die", although this is included.
- Not just "endless duration", the duration follows from the relationship.
- Not just "a future hope", eternal life begins now by knowing God-and-Christ.
John 17:3's relational definition matches the rest of John's Gospel:
- John 5:24, "he who… believes Him who sent Me, has eternal life… has passed from death into life" (perfect tense; present possession).
- John 6:47, "he who believes has eternal life."
- John 11:25-26, "everyone who lives and believes in Me will never die."
- 1 John 5:12-13, "He who has the Son has the life… these things I have written to you who believe… so that you may know that you have eternal life."
Eternal life is the relational reality with God, possessed in present tense, consummated in glorification but begun now.
Apologetic significance
The verse engages:
- Heavenly-mindedness vs. relational-Christianity, eternal life is not a placeholder for "afterlife" but a present relationship.
- Watchtower / Arian Christology, see above; the verse is engaged frequently in Trinity disputes.
- Modern religious indifference, to the question "is one religion as good as another?" the verse answers: eternal life is in knowing this specific God-and-Christ, not abstract religious sentiment.
- Universal scope of the gospel offer, knowing God + Christ is open to all who receive Christ (John 1:12).
Key words
- G2222 - zoe, zōē (life), paired with aiōnios (eternal)
- G0166 - aionios, aiōnios (eternal)
- G1097 - ginosko, ginōskō (know), relational, experiential
- G2316 - theos, theos (God), the only true God
- G5547 - christos, Christos (Christ), paired in the relational object
- G0228 - alethinos (pending), alēthinos (true), qualifying theos
Connection to other passages
- John 17.5, Christ's pre-incarnate glory (the very same prayer)
- John 17.22, glory shared
- John 5:24, present possession of eternal life
- 1 John 5:11-13, life in the Son
- Romans 6.23, eternal life as gift
- 1 Thessalonians 1:9, "turning from idols to serve a living and true God"
Quoted in
- Argument from Purpose Meaning and Hope
- Arianism
- Christ Was Made (Misread Proof-Texts)
- Christian God is the Only True God
- G0166 - aionios
- G1097 - ginosko
- G2222 - zoe
- G2316 - theos
- GodLogic vs Jacob Hansen, Is The Trinity Biblical (GodLogic 2026)
- H3045 - yada
- log
- Monotheism
- Necessary Being is an Intelligent Mind
- Pragmatic Argument
- Tree of Knowledge Objection
- Tree of Knowledge Objection Defeater
- Trinity vs Oneness vs Modalism vs Arianism
- Young's Literal Translation
Scripture quotations taken from the New American Standard Bible® (NASB), Copyright © 1960, 1971, 1977, 1995 by The Lockman Foundation. Used by permission. All rights reserved. www.lockman.org