Why people say revenge does not help to heal?

I think that revenge help this is in condridiction to all believes.

When you revenge is the fastest way to heal. After someone did something bad for me and I revenges.

I finally can say ´´Now you are forgiven´´and move on and forget this thing with sense of pride.

I don't agree at all that revenge create more suffering.

The thing about revenge is that something you need to break the law and possibly sit in jail for years. So it make you consider revenge.