Why did you despise the word of the Lord by doing what is evil in his eyes? You struck down Uriah the Hittite with the sword and took his wife to be your own. You killed him with the sword of the Ammonites….
Then David said to Nathan, “I have sinned against the Lord.”
Nathan replied, “The Lord has taken away your sin. You are not going to die. But because by doing this you have shown utter contempt for the Lord, the son born to you will die.” – 2 Samuel 12:9, 13-14, NIV
One of the most famous stories concerning adultery is about King David and Bathsheba. He sleeps with her and tries to get her husband, Uriah, to sleep with her so that he does not suspect her child is not his. Uriah does not do this. So, King David has him killed by strategically withdrawing so that the enemy does the dirty murderous deed. Prophet Nathan is confronting King David about all this sin in the above quoted verses.
Three things strike me:
1) Uriah is never, ever blamed for David’s adultery. The blame is fully upon King David. And he completely owns it (and that’s why I think he recovers after great personal cost).
2) King David recognized his sin is primarily against the Lord. While he certainly sinned against Uriah (as the story indicates prior to these quotes), King David correctly realizes that murder and adultery are sins done in contempt of God. Proper teaching on adultery ought to acknowledge this. Adultery is not just an affront to the faithful spouse; it is a demonstration of utter contempt towards God as well.
3) Consequences for King David’s adultery did not go away with forgiveness. He suffered the loss of his first child with Bathsheba and was publicly humiliated with one of his sons, Absalom, sleeping with his concubines in the open (2 Samuel 16:21-22).
So, what did forgiveness mean in this situation? King David was not struck dead on the spot (see vv13 above). This goes back to a proper understanding of the serious nature of adultery. Mercy is not killing an adulterer or adulteress according to Scripture (Deut 22:22). That’s it. And I encourage such mercy. However, I do not see Scripture teaching entitlement to a continued marriage for the adulterer/adulteress regardless of response afterwards. That decision is completely in the faithful spouse’s hands.