In my view, not to forgive is to create energy blocks, literally. Ultimately, we get ill. Not to forgive creates festering wounds in one's psyche. It prevents us from enjoying life. We get stuck.

I totally agree with psychoslice. I am not sure I say this right: All in One and One in All. Jesus said "Whatsoever you do to the least of my people, that you do unto me.” God knows when a leaf falls because He is that leaf.

So when you do not forgive, you do not forgive yourself, literally, because the person you do not forgive is part of the One and the One also is you.