Ratter - if you are a member of a church, it is a fundamental requirement that you share the beliefs of that Church.
A member may question his faith and his belief, of course, but the practice of attending Church is to be praise God with like-minded people in the ways and belief of that particular Church, and to follow the teachings of the holy book as interpreted by that Church.
All Christians believe that Jesus is the son of God, and believe in the Holy Trinity. But Catholics and Protestants are very different.