The whole idea of God lowering himself to the level of his creation - sort of - temporarily but sort of permanently for the purpose of demonstrating love and salvation through suffering and sacrifice...it's so obviously metaphorical. You really have to invoke some tortured reasoning to imagine that the execution of Yeshua Ben Yosef, if he even existed (more likely a composite of several charismatic spiritual teachers who were popular at the time) is somehow a uniquely meaningful one.
I can see how it would be useful for a god....but only one that is not already all-knowing. The experience of living as a human might give a goid insight into what it is like to think and live and feel as a human. Trouble is, that only works if the god in question does not already know what it is like to be human. For Jesus earthly life to be relevant in that way admits that before him, Yahweh had no real understanding of his creation....which might account for a lot. Could even be said to be a god that KNOWS he's screwed up, and is trying to learn to do better.
However, it would ALSO require that his manifestation on Earth be just like any other person - and so no super powers, no "message", no meaning other than just living....otherwise he wouldn't "get" the whole human deal. If a god ever took human form to know what it was to be human, he would have to live just like any other of us, and only find out after "dying".
Which feeds back into the sacrifice part. Its a sacrifice ONLY if Jesus had no idea who he was, and what would happen to him after death. And if we assume all his miracles were real, then we can see that he must have had a pretty good idea that he was someone special, right up to "why have you forsaken me"? That he was sure he led a "charmed life" right to the end - when it was already tto late to matter.
