The influence of the Catholic Church may seem profound to you, but the many other faiths have had equally profound influences when seen through the eyes of their believers. What you are seeing is the hand of man, not the hand of God. The Bible, like all holy books, is entirely the work of humans. As such it contains some practical human wisdom buried under a mountain of human fears, superstition, myth, prejudice, and general ignorance. Your premise seems to me to be suffering from the Bandwagon Fallacy, at the heart of it. Influence merely means popularity.
By the way, I applaud your relatively progressive attitude (for a Christian) about gays and gay marriage. But the important political question to me is, how do you feel about the separation of church and state?