I agree with everything Tiberiu says here. Excellent advice. My go to Enhancers are: DotF: If I've got a strong Religion and I'm not worried about spread to my cities, I love the sense of security this gives me. Makes the game less stressful. Religious Tests: If a neighboring Civ founded before me, and I know I'm going to have to fight for my religion after I take advantage of whatever goodies the AI Religion gives my expos. Cheaper Prophets: For the reasons Tiberiu laid out, but also for the help in defending your own religion. I rarely take Spreads Further. As alluded to a few times on this thread, I don't really like giving my good religions to the AI. I want it to be just strong enough to convert the nearby CS. That usually gives me ~8 cities with my religion, which is ally enough to keep my religion intact. I will confess to never discovering the mechanics of Spreads Further, so I could be missing something here. Does anyone have any insight here?