Theology: Does the Bible Support Same Sex-Marriage?

According to Prof. Robert Gagnon, no.

In his piece, he addressed the question of analogies to slavery. Excerpt:
Scripture shows no vested interest in preserving the institution of slavery but it does show a strong vested interest from Genesis to Revelation in preserving a male-female prerequisite. Unlike its treatment of the institution of slavery, Scripture treats a male-female prerequisite for sex as a pre-Fall structure.

The Bible accommodates to social systems where sometimes the only alternative to starvation is enslavement. But it clearly shows a critical edge by specifying mandatory release dates and the right of kinship buyback; requiring that Israelites not be treated as slaves; and reminding Israelites that God had redeemed them from slavery in Egypt.

Paul urged enslaved believers to use an opportunity for freedom to maximize service to God and encouraged a Christian master (Philemon) to free his slave (Onesimus).

How can changing up on the Bible’s male-female prerequisite for sex be analogous to the church’s revision of the slavery issue if the Bible encourages critique of slavery but discourages critique of a male-female paradigm for sex?

Much closer analogies to the Bible’s rejection of homosexual practice are the Bible’s rejection of incest and the New Testament’s rejection of polyamory (polygamy).

Homosexual practice, incest, and polyamory are all (1) forms of sexual behavior (2) able to be conducted as adult-committed relationships but (3) strongly proscribed because (4) they violate creation structures or natural law.

Like same-sex intercourse, incest is sex between persons too much structurally alike, here as regards kinship rather than gender. Polyamory is a violation of the foundational “twoness” of the sexes.

The church I'm a member of is part of the PCUSA denomination that is currently voting on whether to alter the following language as a standard for ordination of ministers:

Those who are called to office in the church are to lead a life in obedience to Scripture and in conformity to the historic confessional standards of the church. Among these standards is the requirement to live either in fidelity within the covenant of marriage between a man and a woman, or chastity in singleness. Persons refusing to repent of any self-acknowledged practice which the confessions call sin shall not be ordained and/or installed as deacons, elders, or ministers of the Word and Sacrament.

If this standard is repealed, the new wording would make it likely that ordination of practicing homosexual pastors would be allowed.