Orthodox Rabbi Shmuley Boteach makes a bad case on this video for regarding homosexual practice as a purely religious offense rather than a moral one.
Of course, to assert as I will do here that homosexual practice is a moral offense is not to deny that it is also a religious offense. Every moral sin is at one and the same time an offense against the Creator. Take the seventh commandment, the prohibition against adultery, which Rabbi Boteach classifies as a moral rather than religious commandment since it belongs to the second half of the Decalogue. Yet David acknowledges to God in his adultery against Bathsheba: "Against you, you alone, have I sinned" (Ps 51:4). Rabbi Boteach's problem is not that he characterizes the prohibition of homosexual practice as religious but that he does so to the exclusion of it being a moral offense.
Here are six problems with his position:
(1) In the Levitical chapters on sex laws (18 and 20), the prohibition of homosexual practice appears alongside the prohibitions of incest, adultery, and bestiality, all of which are clearly moral prohibitions, all of which are also called "iniquity" or "sin" (18:25). Yet he clearly recognizes adultery as a moral offense. Does he regard incest and bestiality as merely religious offenses that he would be glad to see the state permit?
(2) The tenth commandment includes a prohibition against coveting "your neighbor's wife," which clearly presupposes a male-female union (to say nothing of the 5th commandment to honor your father and mother). The prohibition of adultery (7th commandment) in ancient Israelite law always refers to a man taking another man's wife.
(3) "Noahide law" in early Judaism regarded the prohibition of homosexual practice as incumbent on all people, not just Jews. Similarly, the sex laws in Lev 18 apply not just to Israelites but also resident aliens (non-Jews). The Jewish philosopher Philo of Alexandria classified the sex laws of Lev 18 and 20 under the rubric of the prohibition of adultery.
(4) The words of Gen 1:27c, "male and female [God] made [humans]" and Gen 2:24 ("For this reason a man may ... become joined to his woman and they [or: the two] shall become one flesh") belong to the very foundation of creation. Indeed, the Essenes at Qumran referred to Gen 1:27c as "the foundation of creation" and predicated the rejection of polygamy on them. The Palestinian Jewish messianic claimant, Jesus of Nazareth, similarly cited Gen 1:27c and 2:24 as a basis for eliminating more than two persons in a sexual bond (the duality of the sexes as the basis for duality of number). Homosexual practice is an obvious assault on the foundation of a male-female prerequisite for sex. The Jewish apostle, Paul, viewed it as a violation of Gen 1:27 and 2:24, an attack on creation for which Gentile participants would be held culpable (Rom 1:24-27).
(5) In the Hebrew Bible the word to'evah ("abomination," something abhorrent or detestable to God) is typically used of high sexual offenses (homosexual practice, incest, adultery, bestiality; also cross-dressing), idolatry (including sacrificing one's children to pagan gods, sorcery, and necromancy), and high social offenses (murder, swearing falsely, oppressing the poor). Yes, in Deut 14:3 unclean animals are referred to as "abhorrent things," but eating them is not said to be an "abomination."
(6) Merely ritual offenses can be rectified by ritual bathing and the going down of the sun; they are not capital offenses. Ritual offenses typically penalize both inadvertent and advertent (intentional) acts; moral offenses only intentional acts (including homosexual practice, incest, adultery). Some ritual offenses make the participants contagious to touch; moral offenses never do.
Rabbi Boteach apparently has not kept up with Jewish scholarship on the biblical text. Jonathan Klawans, professor of ancient Judaism at Boston University, wrote in his book Impurity and Sin in Ancient Judaism (Oxford University Press, 2000) that the sex laws in Leviticus 18 provide a classic example of moral, rather than merely ritual, impurity offenses. Even Jacob Milgrom, professor emeritus in his massive 3-volume commentary on Leviticus for the Anchor Bible series, explicitly labels the sexual offenses of Leviticus 18 and 20 as instances of “moral impurity.” David P. Wright, professor of Bible and Ancient Near East at Brandeis and an expert on purity laws, has written in the entry “Unclean and Clean [OT]” for the renowned Anchor Bible Dictionary (Doubleday) that in the Hebrew Bible “calling those involved in improper sexual relationships impure is a way of calling the persons sinful” (6:734).
Is divorce a far greater threat?
In addition, Rabbi Boteach claims that the real killer of Western civilization is not “gay marriage” but high divorce rates among heterosexuals and the effect that divorce has on children. He also contends that a consensual homosexual relationship does no harm.
No one is denying the tragic effects of high divorce rates. But Boteach’s argument is akin to claiming that the real killer of Western civilization is not adult-committed relationships between close kin or among three or more persons concurrently but rather the splitting up of marriages consisting of two unrelated persons. It is fairly obvious that entrance into an inherently unnatural union is worse than dissolution of an inherently natural one.
Homosexual unions, like incestuous unions and “plural marriages,” fare significantly worse than heterosexual unions as regards exclusivity and longevity. Not surprisingly, given gender differences, male homosexual activity is far less monogamous than female homosexual activity and characterized by a much higher rate of STIs. Female homosexual unions on average last less long than even male homosexual unions—due in part to the fact that women are more likely than men to have higher expectations of a spouse, to make excessive demands of their partner, and thereby to put higher stress on the relationship. Lesbians also have a higher rate of mental health problems. "Gay marriage" will not radically improve these disproportionately high rates of measurable harm because, quite simply, they arise from fundamental differences between males and females. Even in "marriage" there will be an absence of the moderating influence of a true gender complement.
The root problem of homosexual practice is that it dishonors the sex or gender of the participants by regularizing the deception that each person is only half his or her own sex. It also promotes that view to some impressionable youth who, while still forming their sexual identity, might be encouraged to engage in homosexual practice and build an identity around it. We also have numerous examples that when homosexual unions are promoted the civil liberties of those who oppose such unions are attenuated in various ways. Finally, a male-female prerequisite is a foundational sexual ethics concern, the basis for extrapolating prohibitions against incest and polygamy.