Which of the Ten Commandments does homosexual behavior, particularly a loving homosexual relationship, and better yet a same-sex marriage, transgress? I am the Lord thy G-d, thou shalt have no other G-d before me? No. Thou shalt not make graven images? No. Remember the Sabbath Day to keep it holy? No. Honor thy father and thy mother? No. Thou shalt not murder? No. Thou shalt not steal? No. Thou shalt not commit adultery? No. I think you get the idea. The Ten Commandments still remain.
Ah, but what about the details within the Law? What about Leviticus? Well, what about it? The Law forbids and also requires a lot of things which most non-Jews do not participate in, with no one commandment more important than another: such as the laws of purity in dietary matters, the law of observance of the Sabbath Day (also one of the Ten Commandments, as you know), the laws regarding the major Holy Days and festivals, and so forth. These laws are violated on a daily basis by both Jews and non-Jews alike. So should we throw out the Law altogether, particularly since it has been either fulfilled or superseded by Jesus and His commands? I think both Jews and Christians would say no. Why not? Many Christians might say because Jesus created a New Covenant, which is at once the fulfillment and embodiment of the Old Covenant, and we follow this. Some Jews might say because it gives us something good to strive for, an ideal, even if we fall short. Other Jews might say because certain moral principles are still worth following, such as those listed in the Ten Commandments, while some of the details of the Law can be interpreted in different ways, just as Jesus, a revolutionary rabbi, interpreted the Law in a different way. Homosexuality is one of these topics that may be and have been interpreted according to the Hebrew Bible in more than one way. I have discussed this on several threads (maybe even this one) and therefore I will not go into detail here. However, Christians might then protest: but what of Jesus’ interpretation of homosexuality in the Gospels? What of it? Christians are not bound by the details of the OT, and Jews are not bound by the details of the NT. And so on.