The evidence is the profound effect God has on billions of people's lives everyday.That is if you think yuou have a right to any evidence at all.
But if people really believed in a unicorn and thought this unicorn was going to guide them through their lives...........there would be a profound effect on those people, but that doesn't mean that unicorns are real and exist.
The Bible was written by men, was it not?
Written physically by men who were inspired by God. He told them what to write, sometimes verbatim, other times just the gist of it to make it more relatable to humans.
So God told them what to write about slavery? Even Exodus 21?........where it clearly states that owning slaves is supported by god? Not only is god condoning owning slaves, he tells who to buy them from and how to treat them.
I think that owning people as property is immoral. Why am I more moral than your god?