"Jesus would rather kill, not marry, gay people" - Franklin Graham

[SteveII]

You don't thing the very very clear prohibitions and judgements covers God's opinion on homosexuality and by extension gay marriage?

Well, at least now you're acknowledging that the Christian attitude toward gay marriage is "by extension" of what is in the bible, rather than an affirmation of something actually present in the bible.  At least that's progress.  I will also note that, contrary to the way you frame your question, the bible actually says nothing about homosexuality, but rather addresses specific homosexual acts, not homosexuality as an orientation. But thank you for acknowledging that the Christian complaint about hating the sin and not the sinner is essentially bullshit.  But let's talk about what the bible actually does say.  First of all, I have to ask which part of the bible we're referring to here.  Because if you mean passages in the old testament, we no longer hold that people are abjured against eating shellfish or wearing cotton-polyester blends either, so I think we can ignore those prohibitions.  That leaves us with Paul's statements in Romans, if I'm not mistaken.  It's worth noting that neither Paul nor the writers of the old testament had any notion of homosexuality as an enduring sexual orientation, much less any concept of gay marriage as such.  So by necessity, the comments against homosexual sex are referring to sex outside marriage.  Is it right to extend these statements to statements as to how God feels about homosexual sex within marriage?  Can we likewise extend the prohibition against heterosexual sex outside marriage to what it should say about heterosexual sex within marriage?  I don't think so.  So anyone making such an argument is being ignorant.  But beyond that, even if we accepted that the new testament does say something about gay marriage, we need to look at how Christians actually apply the messages of the new testament in order to see if a coherent moral position is being advanced.  We note that Jesus explicitly condemns divorcing and remarrying, and he also speaks without censure about slavery.  Yet modern Christians take neither message to heart, ignoring what the bible says about divorce, and excusing Jesus' comments on slavery as being merely a product of the time (or perhaps progressive revelation).  Yet how do they treat the passages referring to homosexual behavior?  They zero in on those passages and extend them to things they weren't even talking about at the time.  And why do they do this, but ignore messages about divorce and slavery?  I contend it's because they like the messages condemning homosexual acts, and not the others.  Christians are picking and choosing what to affirm and what not to affirm based upon prior prejudice, rather than upon anything the bible actually says.  And cherry picking which parts of the bible to obey is not a rational procedure no matter how you choose to frame it.  The contemporary Christian, rather than being motivated by any hypothetical argument such as you make, is actually motivated by one thing: anti-homosexual prejudice.

1. You want to dismiss the OT because we can eat shellfish today? You are failing to distinguish between moral laws and laws for managing a theocracy. Sodom and Gomorrah were centuries before any theocracy/laws. No moral laws of the OT have ever been set aside/abolished/sunsetted.
2. Your assumption that Paul and the OT writers had no sense of homosexuality as an enduring sexual orientation has no substance. There were whole cultures where such things were common. Sodom and Gomorrah obviously had wide open ideas on this issue. The reason it does not warrant a mention is that there are a hundred different ways to be oriented toward sin--which was clearly the focus and reason for the NT. What makes this one special? 
3. The divorce analogy is very weak. You can find millions of people that think divorce and remarriage is morally wrong. Personally I think unless there is infidelity or abuse, remarriage violates the command of Jesus. If you find examples of special pleading, take it up with that person/group. The Bible does not special plead. 
4.  Why would Jesus single out chattel slavery in the Galilean countryside while speaking to the poor and working class?  Slavery has multiple definitions and cultural/social aspects to unpack and is a red herring. "...and love your neighbor as yourself for all the laws hang on these..." seems pretty clear you can infer the morality of thousands of things that didn't apply to the audience or haven't been invented yet. The difference is that homosexual acts were singled out in the OT and the NT. Christian's can't ignore it, because a cafeteria Christian undermines their own system of belief--even if they don't realize it (as you are pointing out). 
5. I don't like many contemporary Christians. They have piss-poor theology and made a mess they can't reconcile.
6. Reminder: everyone is a sinner. Homosexual acts don't have a special place. 
7. An appropriate Christian response is to love the sinner, don't compromise on the sin, but let God deal with it--it's not our job to change people's lives. 

If you want to focus in on one or two responses for more discussion, NP, just let me know.