Except that Christians have been doing all that stuff the entire time. Because the book said they could.
Modern secular society looked at all the harm done by religion and decided those things were wrong all by ourselves. That’s the power of democracy for you. It’s so much better than taking life advice from ancient people who beat each other to death with rocks.
So I’ll ask you again. Why do YOU think genocide, slavery, rape, child abuse, and torture are wrong? Is the Bible the word of God? Is it just another book written by men? Or did Satan write it pretending to be God?