Don't confuse religion, religious belief, theology, and a "church."

A church (and I'm not talking about a building) is a group of people who come together because they disagree about their religious beliefs less than with the religious beliefs of other people.

Theology is the human attempt to understand the structure of the Underlying Principle of a religion.

Religious belief is that body of belief, mores, and teachings that a particular church agrees upon.

Religion is what's left. When examined, religion doesn't differ from one church to another.

These statements seem to be true of ALL religions, not just that which is called "Christianity."