Right right right. Here's my little cozy opinion.
First off, "should gay marriage be legal in all countries" The answer (for me) is yes. People spend way too much time worrying about other peoples decisions, and don't focus enough on themselves. In the media, we have celebrities, and many people are more concerned with their lives that their own.
On this post, I've seen many people voice concern over the fact that it is a "destructive lifestyle" both socially and physically. I totally understand how it would be destructive socially, since gays in our society are sometimes called out etc. However, saying that it is a destructive lifestyle physically is a bit of an assumption. Someone pointed of because of diseases and what not. But thats assuming that all homosexuals have sexual relations.
Of course, religion comes into play, and that is something I'll never be able to debate, as most people are very set on their beliefs. I say, believe in what you want to believe, as long as it doesn't affect other humans in a negative way. Once it crosses the line, your "freedom of religion' does not apply.
Oops.