I believe in God because there is no way all the moments that have strung multiple events together in precision just to piss me off could have been a fluke.  not that often, not that creatively.  God is having fun.
Also even those who don't have a religion, the way they think, the way they make up their minds is actually influenced heavily by religion.  It's a complex thing to understand... but basically your morals, your reactions, your instincts etc. are largely shaped by the religious effects on culture.  the two by the way, strongly entwined.