Is there a difference in attending a wedding for a gay couple and one for a couple that is living together? What about if the bride is pregnant?
The moral Law is spiritual, so anyone who has as much as looked with lust has committed adultery in the heart (see Matt. 5:27,28). It is therefore not unreasonable to conclude that in some way every couple has sinned sexually in God’s eyes—whether they are physical adulterers, adulterers-at-heart, or fornicators, pregnant or not. However, by getting legally married they are fulfilling God’s plan for a man and a woman, because He is the One who sanctioned the institution of marriage (see Gen. 2:24, Matt. 19:5,6). Every wedding I have attended falls into this category.
However, “marriage” between homosexuals has never been sanctioned by God. Marriage is God’s institution and He said it is between a man and a woman. Two men or two women cannot be married. So when gays are “joined together in holy matrimony,” it is as meaningless as a man being married to his dog or cat, hoping for God’s blessing on bestiality. God has never authorized such a union, nor such behavior. God’s Word says, “If a man lies with a male as he lies with a woman, both of them have committed an abomination” (Lev. 20:13).
Deuteronomy 7:3 Nor shall you make marriages with them. You shall not give your daughter to their son, nor take their daughter for your son.