[MeechMunchie]

I think most religious argument [against gay marriage] comes down not to "I don't think those people are loved by God", but "I'm not comfortable with my religious organisation losing power over this aspect of society."

Faith and gnosticism is a personal philosophy. Religion is a political tool. Organisations like the Catholic Church were established primarily to amass wealth and power while keeping those dirt-eating plebs in line with cautionary ghost stories, and this aspect has been internalised by their followers, usually subconsciously. With that in mind, of course Catholics are upset by gay marriage. It's a violation of the rules their masters set, and that means that people don't feel obligated to have their actions cleared by the Pope any more. In other words, it's another puppet string that's slipped out of their hands.