I think if you are in US, If you are a mormon, the chance will be higher,. In mainland china, you almost have no chance. I have many mormon friends, they are nice people.
BYU have good reputation in US. The accounting is very strong in BYU.
You don't need to be a christian, but you need to be interviewed by a Mormon priest. By the way, you should sign a contract promising that you don't smoke and drink while in BYU.
I know something about Christianity. Is it helpful? If only no smoking and no drinking, I think most chinese women can handle it. But why not coffee and tea? Is there really no chance for mainland chinese? How about the party members?