Whereas Jews had always thought of life coming only from Yahweh, he made it possible for the son to be the source of life. He permitted him to have life in himself, to be a lifegiving spirit (πνεῦμα ζῳοποιοῦν), as Paul stated (1 Cor. 15:45). Only God could have been considered the life-giving spirit, but he shared that with Christ, according to both John and Paul. If you weren’t so stubborn, you’d agree with me. What I’m saying isn’t controversial.
I would like to point out that in Paul it's what Christ became (γίνομαι), a life-giving spirit, and not something granted to someone who already had the capability.