You're right about the OT. I thought some theologians had reasoned that Soddom and Gommorah were destroyed because of rape and violence, but maybe that's not true? Im not a fan of the OT anyway, but it does have important stories in it. But you're right about the condoning of genocide, slavery, etc. Like when Noah condemns his son Lot to 5 generations of slavery. That's just evil. So, in my confusion with the OT God who seems to make mistakes and blame us for them, I really like to stick to what Jesus said in the Gospels. What do you think this disconnect between the OT and NT means?
Christianity is currently dominant because it flirts with worldly power, It's not really Christianity at all. I call it Unironic Satanism: the worship of capital, military, imperialism, police, politicians, and reactionary institutions. So, in a sense Original Christianity is essentially dead. Nietzsche wasn't wrong when he said, "God is dead and we have killed him... Who gave us the sponge with which to wipe the horizon from the sky?" This is the state of our current world. We have committed the ultimate blasphemy collectively. We have defiled the sacred and buried it away, all because life is painful and unjust. Who could believe in a God when there is so much vast suffering and unimaginable injustice? It's not even a question for many.
Also, the current form of reactionary Christianity in the West is a fantasy death cult, whereby reactionaries can retreat into a fantasy about apocalypse and rapture that will finally wipe away all of the sin and pain from the world. Sorry pal, that aint happening. We were given intelligence and resources to save ourselves. Hear no evil, see no evil, speak no evil is not a survival strategy, it's the most evil form of ignorance.