Then, how can you say it's Biblical?
Well, if I were to argue....
You can count the number of verses dealing with homosexuality on one hand.
Then you get into what "homosexuality" meant at that time, which dealt more with prostitution and pederasty and religious paganism (when you look at the OT, for the latter) -- those were the images conjured by that word. I think in the text you mention, it specifically referred to the "top" and the "bottom" in religious prostitution, as the connotation went.
The Sodom and Gamorah incident was about inhospitality and gang-rape of innocent strangers, not homosexuals, as per a reference to inhospitality in the NT as well. (Similar to how homosexuality in prison is more about violence and control.)
And you could look at the OT law as developed by Israel to be a contrast to the pagan nations and as part of sexual indulgence and also joining two things that are not alike. Note that lesbianism is not addressed in the myriad of examples. And many other things that are "unlike" are now indulged in by Christians and others without regard to the text.
Paul makes an argument based on what is "natural" but assumes homosexuality in nature as to be what is unnatural. He appeals to the "common sense" of what people might see as natural, when talking to the Romans.
I don't know, but those are the sort of arguments I've seen.
So, along with somewhat of what Oberon is saying, I suppose the final arbitrator here to be how exactly one views the Bible.
Is it God writing supernaturally through people?
Is it a book compiling people's experiences with God?
Is it a book that details one nation's view of what it meant to follow God, in their time and place?
Many of the debates seem to occur because the two sides arguing have a different view of the origin and evolution of the Bible as a document.
Note that this makes things even more heated, because both sides are claiming the Bible as "their own" and saying other interpretations are invalid. The sides are wrestling over ownership of the text and disenfranchising people who disagree. No wonder it gets so heated.
