Feelings of revenge can be part of the preliminary process before a person commits to forgiveness. In other words, the process of forgiveness allows for a period of anger. At the same time, you do not want to act on revenge-feelings, but instead realize that revenge-seeking can harm both you (because of harsh emotions that can lead to anxiety or depression) and the other person. So, feelings of revenge are not part of the forgiveness process itself but can be present prior to the decision to forgive. Forgiving can go a long way in eliminating feelings of revenge.
Learn more at What is Forgiveness?