Homosexuality is an abomination

(1)The Hebrew word, [toevah], sometimes translated as ‘abomination’ or ‘detestable’(2), is also applied to the eating of shellfish(3) in Levitical law, among other things, and seems to be a ritual-uncleanliness term, sometimes used to describe idolatry. Of course, it is not translated as ‘abomination’ when applied to eating shellfish, because abomination is a word specifically chosen in an attempt to paint a particular act as more heinous than the others listed in the same section of law. This is the long-standing translators’ bias impinging on the Biblical text.
Furthermore, the act described as ‘abomination’ was not describing a committed, monogamous relationship between two people of the same gender - which was not a category considered in Bronze Age Middle-Eastern thought.(4) Rather, the ‘abomination’ in question would have been an instance of adultery and/or having sex with ritual prostitutes.(5)

Commentary
1. This line of argument draws from verses like Leviticus 18:22 and 20:13.

2. The more famous word 'abomination' was used in the NRSV, the NKJV, and the NASB. In the NIV it is 'detestable', and the word 'detestable' is more consistently used for the many things described as [toevah].

3. The same word [toevah] is applied to eating shellfish in Leviticus 11:9-12 and Deuteronomy 14:9-10. We are not Hebrew scholars, but the exact same term is used to describe many things that no sane person would describe as an 'abomination', and it is often just used to mean 'idolatry' (ex: Deut 18:9-12). It occurs 103 times in the OT, but is generally only translated as "abomination" with regard to supposed homosexual acts - clearly and regrettably the translators' bias coming through. Practicing sorcery, human sacrifice, eating shellfish, trimming one's beard, consulting with a medium, are all described using the same word. Perhaps the best definition may be 'taboo' since the same word is used to describe acts forbidden to the Egyptians but perfectly acceptable to the Israelites (Gen 43:32 & Exodus 8:26). The fact is, many things described as [toevah] we do without a second thought. Others are entirely foreign to our culture and society. In our context, it is not enough to say something is [toevah].

4. That is, there is no situation whatsoever where the Bible deals with a same-sex act that is not also either adultery or fornication, if not also idolatry. It is clearly 'detestable' for the ancient Israelites to engage in any foreign forms of worship. It is quite possible that to 'lie with a mankind as with womankind' is 'detestable' because it is a form of adultery. It is also possibly 'detestable' because to treat a man like a woman sexually is to dishonor him in the context of Bronze Age gender roles (read: misogyny). No one seems bothered by the fact that it is 'detestable' with no explanation as to why. We are left to guess.

5. This is of course a catch-22 which has apparently paralyzed ordination of LGBTQ folks in the ELCA. Current debate is around what constitutes a "committed relationship". Since we discriminate with regard to marriage rights for LGBTQ folks, one cannot simply point to marriage as a committed relationship. As long as we discriminate with regard to marriage rights, LGBTQ persons will inevitably be vulnerable to the "adulterer" or "fornicator" claims. To date, sex with ritual prostitutes is not a concern.