In the context of Matt. 19:9 and
Luke 16:18, divorce and remarriage is an act of unfaithfulness to the marriage covenant. In that sense, to remarry is adultery. The marriage should not have been done, but now that it is done, it should not be undone. It is a real marriage. Illicit. Adulterous to enter into, but real. Valid. And that real covenant of marriage may be purified by the blood of Jesus and set apart for God. A couple who repents and seeks God's forgiveness, and receives his cleansing, should
NOT think of their lives as ongoing adultery, even though, in the eyes of Jesus, that's how the relationship started.
Deut. 24:1-4 speaks of a divorced women being "defiled" in her second marriage so that it would be an abomination for her to return to her first husband, even if her second husband died. This language of defilement is similar to Jesus' language of adultery and yet the second marriage stood. It was a real, valid marriage.
I'm sure we all know of marriages in the church that are second marriages for one or both partners, marriages that should not have happened, yet today are clean and holy marriages. Forgiven, justified, Spirit-led husbands and wives who are pleasing God by the way they relate to each other. They are
NOT committing adultery in their marriage. It began as it should not have, and has become holy.
Attempting to correlate 'remarriage after divorce' and 'homosexual marriage' is pure poppycock.