I have gotten right with God, the one true God. He has proven Himself thru His Word, science, history, math, archeology, and more. Since I know God to be true and real, His Word is also true. This knowledge is completely freeing. I don't have to wonder about life or its purpose. I don't have to guess if something is right or wrong either. It's amazing!
Now onto the topic at hand. For me to respect someone's belief that participation in sin of any type is ok is to agree that it is indeed ok for them to participate. Since the post was about homosexual sex, let's just use it. For me to respect a person's participation in homosexual sex is to acknowledge that it is ok to do so. God has made it perfectly clear that homosexual sex is WRONG, therefore, participation in or being ok with said participation is also wrong. Period. Dot. End of story. I CANNOT have a different opinion from God. It doesn't work that way.
Now, do I hate anyone who participates? Absolutely not!!! Will in respect their belief that it's ok? No!!! Why? Because to do so tells them that it's ok in my eyes that they are participating. What I will tell them is that I respect their right to be wrong. Their eternity is more important than their liking me in earth.
Back to bullying...it would definitely NOT be ok for me or anyone else to harass those involved in homosexual sex. After I tell them that they are participating in an activity that will send them to hell, I should be done. I don't need to continuously tell them or make them feel badly. Homosexual sex is wrong, and I can respect their right to be wrong.
I hope this clarifies how a true Christian should view this subject.