Do you agree in "specific" religions?

OK so I'm not atheist or anything, I believe in God. But isnt it enough to just say that you believe? I mean, to me, so many different groups of people branch off into their different religions, for stupid reasons!!! I mean when your talking about Jews and Christians that seperation makes sense. But Baptist, Presbyterian, all that....i dont see why its different. Its certainly isnt different enough to lead to all these wars. So tell me what you think? Should we just say we believe or do we really need "religion"?