As a Christian theologian and historian, I can tell you that the scriptures do not contain very much reference material on homosexuality. There are a few mentions of it, and I grant that the references which are there, do condemn homosexuality. However, it should be noted that the scriptures condemn all sexuality outside of wedlock and are suspicious of sexuality within wedlock as well.
According to the Judeo-Christian tradition sex in general is something to be avoided.
Note well, sexual mores did not find their way into the Ten Commandments, other than to condemn adultery.
Jesus did not talk about homosexuality at all.
St. Paul mentions homosexuality in his letter to the Romans 1:26 where he says that it is unnatural and an abomination.
The same word, abomination is also used in the scriptures to describe the act of eating shellfish.
Abomination is a strong term, but one that is used often to describe any activity that is prohibited by the laws that are written in the books of Leviticus and Deuteronomy.
Note well, St. Paul condemns homosexuality, and he would also prefer that every person be celibate. He thought that the best situation for all Christians would be for men to live in communities with men, and women to live in communities with women, and that everyone should be celibate while awaiting the return of Christ.
Of course, he knew that this situation would not obtain. Nevertheless, for St. Paul this was the ideal. As far as Christian idealism goes, it is impracticable, we cannot follow St. Paul.
The human race would be no-where if we did.
We may conclude this, the Judeo-Christian theology does not speak realistically or convincingly on issue of human sexuality.
Jesus was concerned with is justice, not sexuality, but justice, that we have ethical relationships with one another, that we respect each other’s personhood, and treat one another as we would like to be treated ourselves.
When Jesus commented on the law he always turned to this point; love one another as God has loved you. This, to Jesus is the whole of the law and the entire teaching of the prophets, which is something we cannot fulfill if we are busy trying to exclude our neighbors from the full franchise of citizenship.
The issues presented in the struggle for marriage equality is one of Justice.
Moreover, the freedom to marry is about more than marriage equality, it is about equality per se.
It is about justice, and the rights of citizenship.
It is about a recognition of the principles that are at the foundation of our social order, the truths that we hold to be self-evident, that all people are created equal and endowed by their creator with rights that are inalienable, and that among those rights are life, liberty and the pursuit of happiness.
There can be no traditions in America that are not in the service of this tradition.
To deny American women and men the right to marry the person of their choice, or to deny to American girls and boys the hope of future happiness, the right to determine the course of their own life, to deny them their liberty, is a gross violation of the American way.