Would you please help me make this argument regarding homosexual intimacy and religion (no i'm not on the neverending soapbox)

Okay in the interest of human rights I’ve been faking a little bit. Faking like I know something about the Bible…. Oops. There were some very mean-spirited remarks on a friend’s facebook page and with the friend’s permission I have engaged in a conversation about them with the poster. Surprisingly the poster is willing to hear what I have to say. But I’m stuck.

I think this is the short version: Original post by friend: “God loves everyone including gays, illegal immigrants, etc… so please love them as well”. The response that was mean-spirited said basically “well gays are an exception because they commit sins over and over and they don’t apologize for it”. Then I said that she should love them no matter what and stop judging. She said it’s not judging it’s calling a spade a spade. I said it is judging because its stereotyping. She conceded that it was stereotyping. But that she believes gay sex is a sin. I said she can believe whatever she wants so long as she doesn’t use it to hurt others. And that we all commit sins so don’t spread the hate. And I said something else , trying to get on her track of thinking, that even though I don’t believe it is a sin , that “gays” could apologize for their sins and thus be forgiven (she implied in almost every post that they couldn’t because the sex is a repeat offense).

Okay so her last response was this “If you look at the old testament in its list of do’s and don’ts, you will see that there are somethings that get you a mild punishment, there are things that will get you banished, there are things that will give you a death by stoning. Then there are a very very few things within the stoning level sins that are labeled as an “abomination”. Please tell me why gay sex is listed as so much more bad than the other stoning offenses.”

What does this even mean and how can I respond? The only reason I put so much effort into it is because she is actually listening to me so perhaps I can plant a seed.