As in the days of Lot.

Romans 1:26-28, “For this cause God gave them up unto vile affections: for even their women did change the natural use into that which is against nature: And likewise also the men, leaving the natural use of the woman, burned in their lust one toward another; men with men working that which is unseemly, and receiving in themselves that recompence of their error which was meet. And even as they did not like to retain God in their knowledge, God gave them over to a reprobate mind, to do those things which are not convenient.”
Sadly many Christians support Same Sex Marriages either by openly supporting this travesty or remaining silent and refusing to get involved. Silence means approval in this case.
You cannot call yourself a Christian and be a supporter of Same Sex Marriages. It is against the word of God to support any homosexual agenda. The bible says it is sin period.
Leviticus 18:22
22 "`Do not lie with a man as one lies with a woman; that is detestable."
Leviticus 20:13. "If a man also lie with mankind, as he lieth with a woman, both of them have committed an abomination: they shall surely be put to death; their blood shall be upon them."
1 Corinthians 6:9-10
9 Do you not know that the wicked will not inherit the kingdom of God? Do not be deceived: Neither the sexually immoral nor idolaters nor adulterers nor male prostitutes nor homosexual offenders
10 nor thieves nor the greedy nor drunkards nor slanderers nor swindlers will inherit the kingdom of God.
Romans 1:25-27
25 They exchanged the truth of God for a lie, and worshiped and served created things rather than the Creator-- who is forever praised. Amen.
26 Because of this, God gave them over to shameful lusts. Even their women exchanged natural relations for unnatural ones.
27 In the same way the men also abandoned natural relations with women and were inflamed with lust for one another. Men committed indecent acts with other men, and received in themselves the due penalty for their perversion.
Genesis 19:1-29 says God destroyed Sodom and Gomorrah because of homosexuality. It stinks in the nostrils of God. Genesis 13:13 identify the men of Sodom as exceedingly wicked sinners. Genesis 18:20 says that the sin of Sodom is "very grievous." Genesis 18:23 adds emphasis to the portrayal of the inhabitants of Sodom as "wicked." Genesis 18:24-33 shows that God could not find even 10 righteous souls in Sodom. The perverts who inhabited Sodom, even wanted to rape God's Angels who had come to Sodom to rescue Lot.
It is clear. The same sex marriage agenda is against God, and is SIN, and that my friend is the bottom-line because the Word of Our Most Holy God says so.