Didn't most religions start as a way for people in power to keep ignorant, uneducated peasants under control?

As a leader in ancient times, people could only be controlled by the threat of force to a certain degree, before they start to rebel. But, if you tell them that some mysterious god will punish them for eternity, they buy it and act accordingly. Anyone at least think it's a good theory? And don't go quoting the Bible for me. I know what it says, and it was written by ORDINARY men, which only furthers my point...