The mind is divided, like a rider on an elephant, and the rider's job is to serve the elephant. - Jonathan Haidt

The rider evolved to serve to the elephant.

Creating gods who can see everything, and who hate cheaters and oath breakers, turns out to be a good way to reduce cheating and oath breaking.

We humans have an extraordinary ability to care about things beyond ourselves, to circle around those things with other people, and in the process to bind ourselves into teams that can pursue larger projects. That’s what religion is all about.

Gossip and reputation make sure that what comes around - a person who is cruel will find that the others are cruel back to him, and a person who is kind will find others are kind in return. Gossip paired with reciprocity allow karma to work here on earth, not in the next life. As long as everyone plays tit-for-tat augmented by gratitude, vengeance, and gossip, the whole system should work beautifully.