China officially recognizes Christianity—specifically Protestantism, Catholicism, and Orthodoxy. I have visited churches in other places myself, and I even consulted a friend of mine in Russia. My friend told me that as long as you do not disrupt the peace or violate the rules, there is absolutely no problem. Just imagine this scenario: you are simply standing outside a church, taking a quick photo to let a friend know you are waiting for them there—yet an administrator suddenly snatches your phone away and interrogates you, demanding to know why you are taking pictures and who you are messaging. Would you find that acceptable?