For me… all things are forgivable. However; the process itself can take years, even decades to let go of the really horrific shit.
I have personally been to hell & have seen human viciousness in action. In order to fully work your way through the abyss, you must come to a place of forgiveness for those who have crossed you. It is the ultimate triumph over their bullshit. Forgiveness is NOT for them, it is for YOU. It is about the restoration of YOUR heart… not the liberation of theirs.
Let me put it to you another way…
Forgiveness is simply cleaning up the toxic energy after a spiritual crime scene. Yes… You can still be relatively HAPpy in your spirit home, having just stuffed your bitterness all down in the basement. But consider this…there is a part of you closeted in the dark down there with it. And like any other storage room, you have stuffed away treasures in there as well. There are things of value in all that crap that one day you might want to go looking for….