As a society, we have created certain rules that we're all expected to follow. You're not allowed to hurt or kill another autonomous human being. You're not allowed to take things that don't belong to you without permission. You're not allowed to commit acts that generally injure your community. These are all good ideas.
But when it comes to individuals, we have a responsibility to evaluate whether or not we should interfere in what are personal decisions. We may not consider something to be "right" according to our own personal beliefs, but we have to remember: Those are OUR personal beliefs. They're for us. We have no right to try to force those beliefs on anyone else! Oh, you can offer them (and it's polite to ask and only do so after receiving permission), but if another person declines to believe as you do, that's their right!
Part of being a fully-functioning, healthy society is the ability to agree to disagree and continue living and loving. Remember that personal choices are just that for every individual on the planet, and everyone has the same right to choose for themselves and to not be harassed by anyone who thinks differently! Live and let live is an excellent motto to guide your steps through this world.