Religion is just a sense of gratitude for existence, plus the idea that the cause of existence has a personality.
That's isn't exactly right, though, because the act of gratitude is already by its nature directed towards a person. It's not an idea, it's an innately human act. If you are an atheist, you can say that we feel gratitude because we are confused about causality, but you can't stop yourself from having that feeling sometimes. Would you want to?