Homosexuality is a stain on our consecration from God. We as Children of God, cannot pick and choose which laws we obey and which ones we do not obey.
Homosexuality is the work of a mind that is tuned to Satan. Just as a Man decides to cheat on his wife in adultery, a Man will decide to cheat on God with homosexuality.
Homosexuality defiles our inner light and clouds our moral judgement. It destroys families and produces no Children. Could it be that's why they call it a Sin?