I lose access to the religion screen midgame, but I am not sure what caused it. The screen shoot is from a few turns later. I tried recreating it but could not find what triggered it. If you guys have question on what I did I be happy to help, but my memory tends to be awful so I might not be of much help.

Oh, that makes sense. I ended up choosing secularism because I had so much extra civics point and thought it would be a waste not to use them. Based off the the description I didn't realize it completely cut you off from religion. Sorry for the hassle.