The future enters into us long before it happens.
Rainer Maria Rilke
“To understand is to forgive” formula is more than just perspective-taking, more than just seeing the event from other person’s perspective. In order to forgive, you also have to understand why what happened had to happen. You have to understand the psychological determinism of the particular "why" that led to whatever happened.
Why is a motive focus. We are far more used to posing this question (rhetorically, with indignation) than to answering it. There is one core motive – the pursuit of wellbeing – and a plethora of ways in which we try to pursue it. Some pursue their wellbeing by going to work, others – by boosting your lawn-mower for a quick re-sale on the way to buy drugs. Motivationally, there is no difference.
Say, you busted the guy red-handed, you ask him what he is doing on your property, in a moment of rare candor, he explains that he wanted to steal your lawn-mower. That’s a goal, not a motive. To get to the core motive, you have to keep on asking questions. Why did you want to steal from me? I needed money. Why did you need the money? I needed to get high. Why did you need to get high? I didn’t want to feel sick (or) I wanted to feel good. Now, there’s your core motive: not wanting to feel sick or wanting to feel good is the pursuit of wellbeing. So, the difference isn’t in the “why” but in the “how” we go about meeting our needs and desires. (Now, to clarify: I am not saying you should try to have a conversation with someone robbing you, I am just using this as a hypothetical exchange to illustrate a point about the motivational fuel that we all run on).
No one’s motivationally evil. Motivationally, everyone’s innocent. It’s just that some of us are less sophisticated (more limited) than others in the modus operandi. Why? That’s exactly the very history that has to be understood in each case. And when we understand this history, the determinism of the mind-specific psychology behind a given behavior/act, we realize something very important - namely, that so-and-so had done the best that he/she could (no matter how much it sucks in comparison to what, say, you would have done in a similar situation), exactly in proportion to the intricate interplay of their nature and nurture. It is this insight that becomes the platform for compassion and forgiveness. After all, we can all relate to doing our best and still screwing up - no saints among us!
So, to forgive, you have to see beyond the behavior, you have to be willing to hear the whole story and to unravel the psychological determinism of the other person’s actions to see the inevitability of what happened, the intricate interplay of nature and nurture that wove into any given fact. And only then you will be able to see the event from their point of view, i.e. you will be able to identify with them and, thus, forgive. But this kind of “understanding” is too much work. And this kind of “identification” threatens our own sense of self. After all, who are we if we can relate to something that we originally thought we couldn’t relate to? And what would this kind of identification-based compassion say about us? That’s just too much thinking and feeling. I am not being sarcastic: I really mean it – compassion is too much work and that’s why we don’t do it. A lack of compassion and unwillingness to forgive is too forgive-able! Can you relate to lack of compassion (yours or others') without judging it as callousness? If you can, you can have both self-acceptance and compassion for others at the same time - nice existential bargain!
Bottomline: if it's human, relate!