I don't have a problem with most core faiths. My problem is with the religions and most often the people running them, that grow up around these faiths.
The Christian religions (I chose these because I'm most familiar with them) seem to be run by the most ruthless people I could imagine. These people would make Enron proud. Squeezing the peasants for their last peso to increase the already rich coffers or condoning if not encouraging racism. And the list goes on and on. Very contrary to what they purport to be the Christian message.
It certainly isn't limited to Christians. The world has seen all to well the Muslim clerics twist the faith to most unreasonable lengths. I doubt if any faith is unscathed in it's application. More people have been murdered and tortured in the name of (fill in god) than any political or economic goal.
