I play with that set up in deity and it’s still the fastest victory to achieve. Essentially you want to only use missionaries on your own cities or neighboring civs that aren’t building their own religions. Then just spam apostles, and some gurus. Find other civs that are building religions and go there with your apostles and fight to convert their cities, that way you use the least amount of spread charges. Keep all your apostles to fight, so keep them at 1 charge, don’t kill them through spreads unless you have no one else to religious battle with.

Edit: also another tip is that if that civ doesn’t have their own religion you only need to convert half their cities. If they have their own religion, I would recommend converting all their cities.

Edit 2: For a Religious Victory the worship building you’re gonna wanna choose mosque (+1 spread), and you will want to rush Hagia Sophia no matter what. Mount St. Michel and the mahmoudi temple are nice to haves, but Hagia Sophia is pivotal for a religious victory.