This is why Gene Roddenberry did everything he could to portray a future where people could live and work together in a fictional Federation of Planets. Anything limited to Earth would end up being too unbelievable. In the 60's, humans couldn't be trusted to build fair institutions or encounter strangers without a colonialist bent. By establishing Earth as only one insignificant planet, the even more insignificant beliefs of religions and despots became silly. To get there, he had to acknowledge'Eugenics Wars' and WWIII: violent transitions from a primitive past.
The power of Competitive Bullying just doesn't go away on its own. We all want to believe in things like freedom, fairness and usefulness, but bullies don't have to care because not following rules is always the winning bet unless rules can be enforced by good people. This is impossible when good people don't know the difference between leaders and bullies. God has always been a bully. Every American president has to pretend that they believe in God.