Why is it that religious people who are taught to be kind and forgiving, can be so hateful?

I don't understand. I have been browsing around the S&R board looking for some insight. I have attended many churches in my albeit short life, from the backyard baptist church (literally behind my childhood trailer park) to the Kingdom Hall, to The Church of Jesus Christ of Latter Day Saints. Yet through all of my spiritual perusing i still have yet to find answers, faith, or even some semblance of sense. And it's not for lack of trying. But so many Christians can be downright hateful to anyone who does not see things their way and immediately close their mind in the presence of a challenge to what they know to be right. Why can't anyone have a nice, peaceful discussion about differences in beliefs? Then maybe some of us can actually be enlightened without feeling like we are about to be damned to hell or burned at the stake... does anyone know an online community where this is possible? I don't show my face in church anymore because being there makes me feel like a hypocrite because i dont know what i believe...