Some Jews and Christians support such unions because of the Bible, not in spite of it. Prominent evangelical seminary president Richard Mouw of Fuller Seminary finds only one biblical passage standing in the way of approving same-sex unions (Romans 1:26-27, a passage about the ways in which the worship of idols is manifested), and at least one evangelical scholar from his own faculty reads the passage differently from Mouw and has changed his position.
In my own denomination (Presbyterian Church, U.S.A.), a majority of the Bible scholars at our church's seminaries believe that covenanted same-sex unions can be morally responsible relationships.
(3) Those who argue that all acts of homosexual intimacy are simply further examples of the epidemic of sexual license that infects our society should get to know people who have tried to adhere to societal preachment and entered heterosexual marriages, have found that they were acting contrary to their personal identities and sexual orientations, and have then established loving, lasting, monogamous relationships with persons of the same sex. It makes a difference in this debate if one is not talking about "those people," but instead about friends, family members, and even fellow church members.
(4) Finally, those who imply that the large majority of the population that is at home in its heterosexuality will crumble in an avalanche of conversions if same-sex unions are given legal status and protection should consider the horrible consequences that people in various societies have risked and experienced because they "came out" as gay or lesbian people. They were not enticed into being gay; they found themselved unable to deny it.
I was distressed by a recent conversation with a legislator in Frankfort about including sexual orientation in a bill to protect students in our schools from being harassed and intimidated because of race, religion, etc. He did not want sexual orientation included because he was convinced that educational material used to promote respect for at-risk groups would not state that being homosexual in orientation is sinful. He seemed to imply that efforts to build understanding and respect for difference would risk an epidemic of homosexuality.
I could not think how to start a reply except to say that I disagreed with his avowed Christian stance for my own avowed Christian reasons.