He [Jesus] answered, "Have you not read that he who made them from the beginning made them male and female, and said, `For this reason a man shall leave his father and mother and be joined to his wife, and the two shall become one flesh'? So they are no longer two but one flesh. What therefore God has joined together, let not man put asunder."
This defines marriage.
"You have heard that it was said, `You shall not commit adultery.' But I say to you that every one who looks at a woman lustfully has already committed adultery with her in his heart.
The thought may not be as serious as the act, but it still counts. Similarly with murder and anger. It's from the sermon on the mount.
For out of the heart come evil thoughts, murder, adultery, fornication, theft, false witness, slander.
The word translated 'fornication' is porneia, and this includes all the sexual sins listed in the OT, including but not limited to homosexuality. Piers Morgan came a cropper on this when interviewing Michael Brown when he (Morgan) claimed Jesus never dealt with homosexuality. Brown knew better!
Everyone has access to the law of God as revealed in the bible. I think you go wrong when you make understanding this dependent on interpretation. Toksvig says the same thing - extremely fallible interpretation. I don't think the passages on homosexuality as a rule require much interpretation if you 'take each word at its primary literal meaning unless the context indicates otherwise'. Some knowledge of the original languages can help, but is not essential. What the text says is what counts. Other parts of the bible do need more careful explanation - divorce, why did God harden Pharoah's heart etc.
The revised interpretations are novel - the sin of Sodom being lack of hospitality goes back to 1954, and many relating to the other passages only 20 years or so. There hadn't been much difficulty getting at the meaning for the previous 2000 years. You can find examples of Joe Biden and Hillary Clinton being against gay marriage less than 20 years ago.
Adultery is immoral, but not a crime. I don't think the bible mandates the government to make homosexuality a crime. I don't like it that some African countries have such laws often inherited from colonial times, but I also don't like western bullying to have them removed.
Israel under the law of Moses was a theocracy, but that, including the penalties of that law, ended 2000 years ago (if Christianity is true), and there is no theocracy now (or unless Islam is true and Judaism false). Notwithstanding some American evangelicals might wish there were!