It really depends on how you read the Old Testament. The very early part of it has God being a pretty brutal thunder god, but by the time you get to the later Prophets, he's a much more peaceful, loving deity. The whole business about turning swords into pruning hooks and all that is from Isaiah. And the God of Israel sent Jonah to Nineveh of all places to preach his word, which was heard, to the point that Jonah was pissed when God saved them, and had to be taught a rather sharp lesson by this universal God. There are many other examples I could mention.
So there was an evolution in the Judaic concept of God. Whether or not you believe that was brought about by God, or by the people themselves, is irrelevant to the topic. The fact remains that Judaism in the time of the Prophets thought very differently about God than it did in say, Exodus. By the time you get to Jesus, all of the disciples were Jewish. All the writers of the New Testament were Jews except Luke, and he was a Jew by Choice (a convert).