You are right. I like the way you put it about revenge and bitterness. Let God handle it.
A price was always paid for forgiveness of sins. Forgiveness is not a get out of jail(no worries) free card. See sacrificial system Old Testament, and Sacrifice of Christ for our sins for more info.
Yes, it is an accessible gift, but it ain’t “free”. Anger and bitterness remains as long as there is no penalty to the perp.
If one thinks it is appropriate to let somebody go after
murdering someone...f’gedda boutit.