same sex marriage
gay people
Gay people would obviously approve of same-sex marriage. This is because that is what they are interested in.
straight people
A straight persons perspective could lean either way because some people could be wildly against it, while others are for it. Of course there are going to be the people who really just don't care either way.
Christians
Most Christians would have a bad perspective on same-sex marriage because it says in the bible, "You shall not lie with a male as with a woman; it is an abomination" Leviticus 18 22
non-religious people
Once again, their perspective could be on either side depending on their beliefs. they could wholeheartedly hate the very idea of same sex marriages or they could be one of the strongest pursuers of it. Anyone could be anywhere on that broad spectrum