Honestly, if I was the leader of a religion, AI would seem like a great tool. Create an agent with live voice chat that is prompted to give all of the religion's fundamental ideas. A single religious leader could create the app, and millions could use it. The leader could assert that the app is designed exactly the way that ${deity} told the leader to design it, so that the followers are essentially talking with ${deity}. It would be just like THX 1138.