forgive

A key insight of Christianity is that forgiveness is something we do for ourselves: it's not just about extending grace to the party being forgiven (though it is also that).

Game-theoretically, forgiveness allows tit-for-tat agents to escape from defection loops, opening the possibility of a better equilibrium for everyone involved.

Psychologically, forgiving others removes poison from our own hearts, and since projection is unavoidable, also makes it easier to forgive ourselves (and vice versa).

A nice insight from NameRedacted:

Acceptance in Buddhist parlance plays a similar role to forgiveness in Christianity. Accepting the world is closer to forgiving the world for being so messed up, rather than any sort of connotation that we won't do anything about it.

"To forgive is giving up hope of changing the past."

Also this tweet:

Forgiveness meditation (TWIM version, Jack Kornfeld's version) is a practice that seems for many people to be a catalyst to unblock them in loving-kindness or other meditation practices, and in their daily life. TWIM positions forgiveness as a kind of 'fallback' if ordinary metta practice isn't working well, which can give the impression that it's a beginner or lesser practice. But this isn't true --- there are stories of advanced practitioners, monks with decades of practice experience, who find forgiveness transformational. Forgiveness is an aspect of loving-kindness, not a separate lesser thing. If you take the frame of forgiveness as acceptance, it's in a sense the entire spiritual path. In the Christian tradition, you might even say that forgiveness is God's primary practice.

A powerful twist on forgiveness practice can be to consider the sentiment "I forgive this situation". We tend to think of forgiveness as personal, about forgiving someone, or asking forgiveness for ourselves. This can sometimes have a contracting effect, reifying the self or other people as unified entities who can be labeled as singularly "good" or "bad", "forgiven" or "unforgiven". So it can also be helpful to take the lens that nothing is personal: the situation is the situation, it may be unfortunate, but it's not in itself about you. In my experience this shift can sometimes unblock some defensiveness and allow forgiveness to flow more freely. It's easier to forgive when you recognize that the situation we're in is inherently difficult.