Hi Valentina,
You put it very well. The whole homosexual marriage issue is so fraught with things like "but I don't hate homosexual people, I just think marriage is a holy institution" it is so difficult. For one thing, the media gived the most positive portrayals of homosexuals, and never shows anything negative. Newspapers and tv are really infatuated with the whole "homosexual lifestyle." I could go on and on. But that's the world when God if forgotten, or ignored. You know, nearly everyone has someone homosexual in their family, me included, and while I'm on good terms with this person, I think his life has been very, very sad. It's a long and complicated situation, but this notion that "marriage" will solve everything is so naive.
On another note, I have a lot of friends who have lived with their bf/gfs without being married, and while I think it's wrong, I guess you also need to look at the person as a whole. We're all sinners, and it's so easy to ignore that one is say, angry and bitter and unforgiving (me), but then I can say "yeah, but I don't live in sin!" I suppose if you can ignore self-righteosness and judging others, you are much closer to living a Christian manner.
Really though, as you and your friends get older, people will respect you for your beliefs. On a quick note: When I was 21 and had my first job, I was totally into punk rock, and an older guy I worked with gave me a Bible tract and started preaching at me. When I look back on those years, I met people who were really kind and compassionate, very good people. I still think of them fondly. This guy however I just regard as obnoxious. I guess what I mean is that we're called to act with kindness towards others, and if we do that, we really make a lasting impression on them.
BTW, my friend's sister calls me "susie" 'cause she's known me since I was ten, but fortunatley, after years of trying I've finally dropped that name!!
Forgive me for rambling on so, I probably have made no sense at all!