A Creature Can Point to Life; Only the Source Can Say 'I Am the Life'
Jehovah alone is the source of life (Psalm 36:9). Jesus received his
life from Jehovah: "the Father ... has granted also to the Son to have
life in himself" (John 5:26), and "I live because of the Father" (John
6:57). What is granted is given, so the Son's life had a beginning.
When Jesus calls himself "the life," he means he is the one through
whom Jehovah gives life to mankind, by his ransom sacrifice as the last
Adam and by resurrecting the dead with authority Jehovah gave him. The
NWT renders Acts 3:15 "Chief Agent of life," and its study note rejects
"Author of life" because Jesus received his life from God.
Some biblical Unitarians add an argument from agency: an agent can
speak in the name of the one who sends him, so the Almighty could
surely make or empower a creature to say "I am the resurrection and
the life." To deny that is to limit what God can do.
Start with what you share: , "With you is the source of life." Then read Jesus' words in the NWT: "I am the resurrection and the life" () and "I am the way and the truth and the life" (). He doesn't say "I bring life"; he says he is it. Scripture draws a line: creatures receive life and point to it. God "gives to all people life and breath and all things" (). Of John the Baptist: "He was not that light, but he was meant to bear witness about that light" (). Moses says of Jehovah, "he is your life" (). Then read : "Just as the Father has life in himself, so he has granted also to the Son to have life in himself." The Son has life the way the Father has it, "in himself," and gives it as the Father does (5:21). A channel can point to life; only the source can say "I am the life." If asked whether God could make a creature who says that, the honest answer is no, and that's no limit on God's power: a creature is, by definition, something that receives its life from outside itself. At the door, leave alone; the NWT punctuates it differently.
Creatures receive life and point to it; only the source of life can say "I am the life." Jesus says it, and says he has life "in himself" just as the Father does.
Jesus is 'the life' only because his ransom sacrifice makes everlasting life possible for us. He is the last Adam, not the source of life.
The ransom is precious, and I agree it's how life reaches us. But when did Jesus say "I am the resurrection and the life"? At Lazarus's tomb, before the cross, and then he called a dead man out of the grave. He didn't say "I will make life possible." He said "I am" it. And 1 John says "this life is in his Son" (), and calls him "the everlasting life that was with the Father and was made manifest to us" (). That life was with the Father before it was made manifest. Adam received life; he was never its source. Why do you think Jesus says "I am the life" and not "I bring life"?
John 5:26 says the Father 'granted' the Son life in himself. If it was granted, it was given, so it had a beginning.
Good, let's read the whole sentence: "Just as the Father has life in himself, so he has granted also to the Son to have life in himself." What was given? Not ordinary life, which every creature gets, but life "in himself," just as the Father has it. That is exactly what a creature can't have, because a creature lives "by him" (). Christians read "granted" in two ways: as the eternal relation of the Father sharing all that he is with the Son, or as the authority given to the Son in his mission (verse 27 says he was given "authority to do judging, because he is the Son of man"). Neither reading says the Son started to exist; both say he has life on the same terms as the Father. What kind of creature has life "just as the Father" does?
John 6:57 — 'I live because of the Father.' That proves Jesus depends on Jehovah for his life.
Read the rest of the verse with me: "Just as the living Father sent me and I live because of the Father, so also the one who feeds on me will live because of me." It's about the Son sent into the world, and it says the believer lives because of Jesus in the same words. If it proved Jesus was created by the Father, wouldn't it also prove we were created by Jesus?
God is almighty. He could create a creature and empower him to say 'I am the resurrection and the life.' An agent speaks for the one who sends him; even Jesus said 'Saul, why are you persecuting me?' about his followers.
God can do anything that is truly something, but "a creature with life in itself" isn't a thing at all; it's a contradiction, like a square circle. That's not a limit on God's power; it's what "creature" means. And look at how real agents in the Bible speak: John the Baptist "was not that light"; Paul says "it is no longer I who live, but it is Christ who is living in union with me" (). They point away from themselves. When Jesus says "why are you persecuting me?" (), it's the reverse: the Lord identifying with his people, not an agent claiming his master's identity. Can you think of any prophet or angel who said "I am the life"?
Psalm 36:9 says the source of life is with Jehovah. It doesn't mention Jesus.
You're right that the Psalm speaks to Jehovah: "With you is the source of life; By your light we can see light." Now listen to the apostle John: "the everlasting life that was with the Father and was made manifest to us" (). The same idea, life "with" God, and John says that life became visible in the Son. Jesus also says "the Son also makes alive whomever he wants to" (). If the source of life is with Jehovah, and the Son has life in himself and gives it to whomever he wants, where does that place the Son?
Acts 3:15 calls Jesus the 'Chief Agent of life'. He's an agent, not the source.
Your study note says the word means "chief leader; one who goes first," and many translations say "Author of life." Let's use your wording; it doesn't change Peter's point. He sets Jesus against the man the crowd asked for instead, "a man who was a murderer" (verse 14): they chose someone who took life and killed the one who leads people into life. And Jesus said of his own life, "No man takes it away from me, but I surrender it of my own initiative" (). Has any agent ever spoken about his own life like that?
Don't answer the "could God create a creature who says I am the life" question with "I don't know"; it isn't a question about God's power but about what a creature is. Don't build on John 1:4 with a Witness; their Bible punctuates it differently and you'll lose the thread arguing about commas. Don't hop from John 5 to other "I am" sayings, Hebrews and the Trinity in one go; stay with "I am the life" until it has landed. Don't repeat the full John 6:57 argument here; give the one-line parallel and move on. Don't dismiss the ransom; agree that it is how life reaches us, then ask why Jesus says "I am" the life. The Witness isn't an opponent: Psalm 36:9 is a verse they love, so let it lead them to the Son rather than using it as a weapon.
(1) Read in the NWT and underline "just as" in verses 21, 23 and 26: the Son makes alive, is honoured and has life in himself just as the Father does. (2) Read and notice that "I am the resurrection and the life" comes before the cross and before Lazarus is raised. (3) Compare with in the NWT ("with you is the source of life" / "the everlasting life that was with the Father"). (4) Check and the study note on in the NWT so you know how they read and can acknowledge them fairly. (5) Practise the doorstep question aloud, then rehearse the likeliest reply ("he's the life because of the ransom") and your answer: "Why does he say 'I am' the life and not 'I bring' life?"