This is a question on which sincere Christians might disagree, as it has to do with the relationship between the church and the state, and between law and morality, both of which are contested topics. To keep it brief, my own view is that even though homosexual practice is a deviation from God’s Word (as is any sex outside of the context of marriage between a man and a woman), I do not believe that it should be a crime.
Why do i think that? Well, in my view, not every sin should be a crime. Murder and stealing are sins and should also be crimes, because they tear at the fabric of a peaceful and ordered society. Some sins, however, like gossip, lying, drunkenness (at home) and pre-marital or extra-marital sex should not be crimes, for they are just an inevitable part of the fallen human condition, practised by many people largely in private, they don’t threaten the fabric of a peaceful and ordered society, and outlawing them would probably do more harm than good. My own view is that homosexual sex falls into this latter category.