Loss of Faith

Every Sunday morning since my father got married I've sat on a red pew in church. My step mother in a minister and my father is her husband. They've been wed since September 2007, and since that time we've been a "family". It feels like their exchanging vows has forced me into the marriage. I don't want to be married.
Sunday service starts at 11 a.m. and before we got married, my father and I never went to church so it does bother me to sit thru service for 3 hours when I'm not totally sold on what I'm being told from behind the pulpit. This past Sunday I had a revelation- not really but that's what I'm going to call it. I figured that I no longer wanted to be associated with the idea of "organized religion", or what I associated with that term. I was raised as a "Christian" (though we never went to church), but sitting in the sanctuary this day I promised myself that I would never fully believe what another human being says about religion. This day, the pastor claimed that Christianity was the way to go and Islam, Buddhism, etc. was not correct and faithful believers of those religions would go to hell. This comment stopped me right in my tracks.
I support believing in (individual) sanctimonious beliefs, but when you claim that everyone else is wrong and you are right- that's where I draw the line. When it comes to the idea of religion, how are individuals able to say that they are solely correct in their beliefs and other are wrong?!!! No one knows what happens after death, us people on earth can only go on what we assume- and that will never be 100% accurate. There are things that we will never know- I believe that life after death is one of those things. People will never know what is in store for them after death until they're buried six feet under, until then speculations are just that- assumptions! I do not wish to be apart of other's people assumptions, if anything, I'd rather make my own and stick to that. Therefore, I declare that I am no longer a Christian. I do believe in a God and higher power, but not necessarily in the form a "structured" religion.