Forgiveness is a defining feature—in fact, the defining feature—of the Christian faith. Of the many systems of justice in the world, across the many nations and peoples and governments, Christianity stand unique in this one respect: “Christian" justice is designed to end up in forgiveness.
We are commanded by Christ to forgive, placing no limits on that forgiveness. But Jesus knew such forgiveness doesn’t come naturally to persons; scars remain, wounds linger, and the impulse to forgive serious infractions remains far off to many of us who’ve been injured. So Jesus told a parable linking forgiveness to gratitude: our ability to forgive flows from our own sense of blessedness and our own experience of forgiveness extended to us.
Forgiveness is taking sin, and sinners, seriously. Christian forgiveness is not the same as permissiveness, moral ambiguity, or acceptance of wrongdoing. Forgiveness assumes the reality of sin, takes it seriously, and extends the grace of God through the community of the forgiven.