[tripzilch]

For people that can't relate to Christianity, and still need some help with the "forgiving" thing, I can recommend compassion meditation, aka Metta meditation.

It's not quite entirely secular either, because it often has roots in Buddhism. Still, you can easily practice it without needing to adapt any Buddhist teachings. I'm not a Buddhist and I don't desire to become one, but some of the practice is quite useful :)

I'm just pointing it out because I really agree with prewett, that forgiving (all sorts of things and people) is a very powerful and positive thing to do. Much more so than I expected before I practiced Metta meditation for a while--it was just one of many different series of meditation types/styles we did with our meditation group. It's had a very profound and long-lasting effect on me, also quite different/orthogonal to the benefits one gains from typical mindfulness meditation. Which I can also recommend btw, but the effects of the compassion meditation seem that more tangible, like it taught me things. Maybe that's just me though.