The Bible is very clear about condemning sexual immorality. But there is but one moral absolute: love, that is, self-donation for the benefit of another motivated by a view of that other as wonderful. While that pole means a lot of human-facing behavior will remain classified as immoral in almost all situations (adultery [although not, perhaps, consensual extramarital sex], stealing, killing), some behavior, like same-sex sexual activity, will be reclassified over time. Culture will condition to what degree a specific act is immoral.