Jonathan and David
That's disputable. I've seen both sides of that argument, at best you can question it. The reference is not conclusive. Not a good defense at all. If you can get past Roman's Chapter 1 and 2, you might have something scripturally, but I doubt it. You'd be better off with the Nobody's perfect, we all have vices defense.

We all carry burdens, there are no exceptions.
Ahem. You can question EVERYTHING in the Bible.
You can Question everything period. Free will is pretty cool huh.
From my perspective, I have a friend that is closer than a brother, this is a platonic friendship. I am familiar with the verses used on your side of the argument, and I know they can be interpreted the way you would prefer, but, it is a presumption, taking a leap, to get there. Interpreting it the more accepted way, actually does fit better all the way around.
My point or suggestion, in relation to the Bible would be to question the validity of precepts and Justification's being from God or Man? Where the Scribes Protecting Principle, through the chronicled word of the Prophets, or running cover, abandoning principle, trying to protect and justify misdeeds of the Prophets and Rulers.
My faith in God is complete, I surrender to it. My faith is not in anything of this world, though I appreciate this world. The Written word is at best other peoples words telling us what God is, and what God is not. Is it inspired, Yes, are there appear to be contradictions, yes. At some point in our lives we all need training wheels, there may come a time when we may even need them again. I believe that we are each meant to see and experience life through our own eyes, our own experience. God gave us Conscience as a guide and barometer, we learn through cause and effect, experience, and what we share. The Gay thing, even Gay Marriage is between you and your Maker, My load under the same Authority. My advice is that you coin a different term other than the word Marriage, be creative, have fun with it.

You will find much more tolerance and support doing that.
Locke followed the two great commandments and built the foundation of his philosophy on them. Jefferson pretty much limited his interest to Psalm's, Proverbs, and Jesus words in the New Testament. We are all governed by cause and effect. Conscience first in all things.