If you are saying that religion can be exploited to justify anything - well that's perhaps true, but the same could be said of any belief system. The two World Wars, the Stalinist purges, the crimes of Mao - none of these were committed in the name of religion. In fact most of the great crimes of recent centuries have been committed in the name of secular ideologies or nationalism. I disagree with you when you say that "religion does a tremendous amount of evil in the world" - I would say that a lot of evil is committed in the name of religion, just as it has been committed in the name of communism or secularism. The key point is that whatever our beliefs are, we tolerate others and remain flexible.