First of all, I will let you know that Nepal is a secular country now. In the past, it used to be a Hindu kingdom. Now all people are equal in terms of religion. The Muktinath temple is open for all visitors whether the visitors are Christian religious people or Muslims. We respect all religions and want some respect from anyone while they are in Nepal. So forget about religions and culture while in Nepal. The main temple is just to see from outside but anyone can enter and walk around the temple compound.