Sticking with the Bible, "in the beginning" God trotted out all the animals for Adam to find a suitable helper or companion or partner, because Adam was all alone. God already tested out goats and sheep and the like for Adam. So, if a man today doesn't find a suitable woman, it seems that God has already given the green light to try something else.
If you want to use the statements of Leviticus as God's Laws against gay marriage, then the same book condemns eating shrimp and rabbit and raw meat, crop co-mingling, wearing linen and wool together. I am sure I could list a hundred other things, but you should get the point.
While the writer(s) don't directly say it, it is clear that one of God's favorite humans (God doesn't kill him for murder and adultery and disobedience and all kinds of mischief) is David, and David had a gay love affair with Jonathon.
The words of Paul against homosexuality are there, but today's translations of the Bible overstate much of what is said with a different tone than Paul intended. It seems that Paul was condemning lusts and fulfilling selfish desires much more than denouncing homosexuality. He was against sexual exploitations such as prostitution and meaningless fornication. Allowing gay marriage should alleviate much of that. I don't deny that there is some homophobia in the writings. I just suggest that before using those words to focus on homosexuals, you better consider the larger context of sexual encounters in general that Paul spoke against.
My biggest problem with GOD SAYS SO as a reason to blast homosexual marriage is that the Bible has been used to justify oppressing women and blacks, justify slavery and the taking of child-brides. Deny it all you want, but if you want to say that the passages about Jesus make you a better person, okay then. But if you want to use the Bible as a whole to determine what is moral and upright, then know this- "People have used the Bible to subjugate women, support slavery, and spread homophobia."
In order to survive, Christianity has had to grow and change. According to many Christians, Jesus said so.
At Matt. 5:7, he said "Neither do men pour new wine into old wineskins. If they do, the skins will burst, the wine will run out and the wineskins will be ruined. No, they pour new wine into new wineskins, and both are preserved."
If you keep using old points of view in the church, when society condemned things such as mixing of races and equality of women and gay marriage, then your church is doomed. Just over 150 years ago, a black man was counted in America as three-fifths of a white man (or as almost a human being). Ask yourself if you want your grandchildren to look at your old point of view against gays the same way you looked at your grandparents old point of view against African American children attending school with their children or even marrying their child. Or try to think about what Jesus said, and grow with society.
If the Bible has truth to it, did Paul go beyond Jesus' thoughts here?
Matt. 19: 11-12:
“Jesus replied, 'Not everyone can accept this word, but only those to whom it has been given. For some are eunuchs because they were born that way; others were made that way by men; and others have renounced marriage because of the kingdom of heaven. The one who can accept this should accept it'.”
Did Jesus just there say that some people are "born that way" and it's okay? Did Jesus just say that some become that way, and regardless of how they got that way, others should accept it?" Say I am spinning this and I will say you are spinning what you say about gay marriage leading to child-victims and animal marriage to humans. It is clear that Jesus said that people who are not attracted to the opposite sex should not marry people of the opposite sex.
Personally, I think the Bible has become something that any group can spin any way to excuse their hatred of others. But if you don't see it that way, I wanted you to see how the issue is not as clear as GOD SAID SO.