Are you kidding me? Religion is supremely useful in controlling and exploiting people. It promises all of the wonderment and fantasticnous you can imagine while also promising the absolute worst nightmares you can imagine, and all you have to do is pay and pray, and the prayers are optional.

"Work in service to your masters and you will be rewarded after you're dead. Defy your masters and you will be punished for eternity" is the perfect tool of control for the uneducated/unintelligent.