You can try to muddle the argument all you want, but
Dictionary definition of judgment:
a : a formal utterance of an authoritative opinion
b : an opinion so pronounced
You're NOT the authority of moral values. Just because you believe so, doesn't make it so.
Telling someone they're "sinning" *is* a judgment. You're parsing words and attempting to obscure.
I am no longer a christian, I left the religion because of how arrogant and judgmental most people are in it.
Can you find a way to provide support, love, and compassion without reminding them that *you* think they're a sinner? Can you?
It's a heroes journey, and you are the hero.
Loving Kindness Meditation will dramatically improve your spirits; give it a try for just 3 days: http://www.youtube.com/watch?v=sz7cpV7ERsM