God didn't need Jesus to die on a wooden cross to save, he needed him to be dead to the flesh to save and that's exactly what he was, dead to the flesh and alive in God preaching the word of truth and life and those who believe in him are saved from this world of sin and death through the power of the Spirit. His words are Spirit and they are life. No need for him to die to save. He lived to save, he was saving in his lifetime.
John 1:29
"The next day John seeth Jesus coming unto him, and saith, Behold the Lamb of God, which taketh away the sin of the world."
Genesis 22:7
"And Isaac spake unto Abraham his father, and said, My father: and he said, Here am I, my son. And he said, Behold the fire and the wood: but where is the lamb for a burnt offering?"