I don't have reasons to agree or disagree. I am sure you have yours and that should suffice

I disagree. If you cannot let go of the anger and hate, it can destroy you. Sometimes forgiveness can start a healing process - it gives you permission to let go of those toxic anger and put yourself together. The forgiveness is for your own mental health, not for the evil doer. I am suffering from anger right now, and hope for the day that I can let go of the hate and get better.

I am in 100% percent agreement with you on this one, however,i think what they are trying to say which doesn't whole much water in reality is,that if you forgive you are no longer holding a grudge that is making you a angry person and anger tends to block positive thinking but that is ok if your grudge is getting you in trouble ,like forcing you to think like the unibomber or the Boston Marathon bombers or school shooters.which is fine except that we are not all mass serial killers . So it works for people with PTSD or such.I had a step-sister who abused me when i was very young and believe me she does not deserve my forgiveness since she is just as big an asshole today as she was 30 years ago,not my place to forgive her ,that's between her and her GOD!