One of the most effective means of giving ourselves immediate relief from anger in our personal relationships is to forgive others.

Many of us cannot forgive those who have trespassed against us.
Something below the level of our conscious awareness prevents us from relieving our residual anger by forgiving the other person and we then carry a grudge in our hearts for thirty years! This unresolved anger poisons our relationship with our friends and loved ones. It even spoils our relationship with ourselves! We make our own lives mean and miserable instead of happy and full. Very often the feeling is, "Why should I forgive them? What they did was WRONG!" But, is forgiveness for those who only do us right? Most people have a hard time forgiving others simply because they have a wrong understanding of what forgiveness is! When you forgive someone, it does not mean that you condone or are legitimizing their behavior toward you. To forgive them means that you refuse to carry painful and debilitating grudges around with you for the rest of your life! You are "refusing" to cling to the resentment of them having done you wrong. You are giving yourself some immediate relief from your OWN anger!

To forgive, then, is an act that we do on our OWN behalf.
It has nothing to do with "lifting" the other person's sin! You are not doing it for their sake. You are doing it for yourself. This is a choice you are making on your OWN terms in order to relieve your OWN pent-up emotions.