“But I say unto you, That whosoever shall put away his wife, saving for the cause of fornication, causeth her to commit adultery and whosoever shall marry her that is divorced committeth adultery.” Matthew 5:32 (KJV)
“But I tell you that anyone who divorces his wife, except for sexual immorality, makes her the victim of adultery, and anyone who marries a divorced woman commits adultery.” Matthew 5:32 (NIV)
Application: This identifies that “fornication” or sexual immorality is being married to another husband or wife while your own private (exclusive), God – joined husband or wife you originally married (but are now divorced from) still lives. The sexually immoral marriage or “fornication” is the only marriage where divorcing of a spouse is permitted by the Lord Jesus Christ, since that marriage was not joined by God.
“What therefore God hath joined together, let not man put asunder.” Matthew 19:6 (KJV)
Application: This establishes that God is the Creator of the marriage HE joins. When He performs the miracle of “making the two one flesh” (because neither the husband or wife already have a living spouse He joined them to) divorce can put asunder / separate a one flesh marriage, but divorce cannot undo it. For the husband and wife that God makes one flesh, the bond is unbreakable (Genesis 2:18-25). Only if the husband or wife passes away is the “one flesh” marriage bond no longer applicable, yet still recognized. (Matthew 1:6, Romans 7:1-3, and 1 Corinthians 7:39)