I fully agree with you, Joe, on the matter of restorative justice rather than retributive “justice”, which, in my opinion, is not justice at all, but mere vengeance as you have indicated. And when the offender has truly repented (had a change of mind concerning his wrongdoing), then forgiveness is in order.
However, I don’t think forgiveness is the essence of salvation (and I’m not suggesting that you DO believe that), but rather deliverance from wrongdoing. (and I hope what I am about to say is not TOO far off the track of your post).
The Greek word “ἀφεσις” (aphesis) is often translated as forgiveness, but the verbal form of the word often means “to leave”. It wqs used in Jesus leaving the crowds to be alone in the hills. It can also mean “liberty.”
For example in Luke 14:18, Jesus said that He was sent to “proclaim ἀφεσις (liberty) to the captives.” It is not the case that He was sent to proclaim forgiveness to the captives as if they had done something wrong in being captured. The captives didn’t need forgiveness; they needed liberty.
In the same passage He said He was sent “to set in liberty, those who are oppressed.” Again, it is liberty that the oppressed need. They need to be freed from oppression. They don’t need forgiveness, as if they had done something wrong in being oppressed.
So Jesus didn’t die for “the forgiveness of sins”; He died for “the liberation from sins” or for “the forsaking of sins” (“ἀφεσις” sometimes means “leaving” or “forsaking”)
If we are being delivered from sin (acts and attitudes which harm ourselves or others) and are on the narrow path that leads to righteousness, then God won’t hold our former sins against us. Of course, forgiveness automatically goes along with deliverance from wrongdoing.
When we look up the reasons for Jesus’ death in the New Testament, we see that every reason is for deliverance from or liberation from sin.
**I Peter 2:24 He himself endured our sins in his body on the tree, that we might die to sin and live to righteousness. By his wounds you have been healed.
II Corinthians 5:15 And he died for all, that those who live might live no longer for themselves but for him who for their sake died and was raised.
Romans 14:9 For to this end Christ died and lived again, that he might be Lord both of the dead and of the living.
Titus 2:14 who gave himself for us to redeem us from all iniquity and to purify for himself a people of his own who are zealous for good deeds.
Heb 9:26 …he has appeared once for all at the end of the age to do away with sin by the sacrifice of himself.**
I know it’s easy to be misled by translations into thinking that Jesus died “for the forgiveness of sin” rather than “for the forsaking of sin”.
For example in the ESV, we read that even John the Baptizer proclaimed a baptism of repentance for the forgiveness of sins.
Mr 1:4 John appeared, baptizing in the wilderness and proclaiming a baptism of repentance for the forgiveness of sins.
Lu 3:3 And he went into all the region around the Jordan, proclaiming a baptism of repentance for the forgiveness of sins.
Now read the actual accounts of what John said and did when he baptized. You will see that he didn’t say a word about forgiveness. Rather you will read that he said a great deal (Matt 3:1-11) about confession of sins and repentance (having a change of heart and mind about them).