From a Christian's POV -
I agree, I think peeps need to do a bit of research into legal marriage and what it actually is. Legal marriage has NOTHING TO DO WITH GOD!!!!!!!!!
Let me repeat that...
Legal marriage has nothing to do with God.
Unless you want to bring God into it with your vows and such, the legal contract on its own has nothing to do with Him. He didn't ordain it. He didn't command it either! Therefore if the gay community wish to partake in a MAN MADE tradition then they should have the right to do so.
It does not and WILL NOT destroy the sanctity GOD'S definition of marriage. It will not destroy that soulful union either. A man made legal contract that someone decides to enter into has no bearing WHATSOEVER on a spiritual covenant that a man and woman may have with God. These are totally separate things.
If you don't believe me....read the bible yourself. Start with Genesis 2 then go onto Matt 11 and see for yourself GOD'S definition of marriage. Not yours, not your church's, not man's, no tradition...no ceremony, no wedding, no priest, no vows! Go and see for yourself! Stop listening to man's interpretation and go back to what your Father in Heaven has actually said.
Gay marriage has not and WILL NOT destroy marriage.