It would be interesting if the moral teachings started with Christianity, but they did not. There are plenty of other philosophical teachings from that time that had great impact on morality without feeling the need to subjugate others. For example, Greek philosophers like Socrates and Aristotle taught about virtue and justice centuries before Christianity. Confucius in China emphasized benevolence and duty long before Christian doctrine existed, and Buddha’s teachings focused on compassion and nonviolence without forcing conversion. These traditions show that moral ideas thrived in many places independently.