Competition

Why is it that there seems to be a competition between different religions? growing up I've always though of religions as opposing sides of a battle for good? Was I wrong when I thought this? My opinions have changed as I grew older, but I still have that in the back of my head. 

True religion

There are countless religions in the world, but some seem to be more legitimate than others, or atleast have that stigma.  Why is it that some seem to be fake or aren't thought of as highly? I couldn't help but think of this while reading a book about Scientology that I'll be doing my final project on. Scientology seems like complete BS to a lot of people, why is that?

Respect

Is it respectful to go to church and not be a part of the religion. Is it respectful to participate in certain aspects of the church without believing in wwhat they represent.  I went to church this weekend for easter and am not catholic whatsoever and do not believe in God. This thought came to me a few times, was I doing something wrong by being there?