The pain of the offence and the cost of forgiving that offence is a double barrel hit for sure, however the only way to freedom from the control the offence has on our lives is to forgive the offender. When you think about it, the offender may never cross your path again but the pain and injustice you suffer could linger for years if you let it.
It is incredible how many people continue in unforgiveness as they think it's a payback they don't realise the only person they are hurting is themselves! They remain stuck with an event controlling their lives for years to come... it won't magically go away. The anger tank will remain filled and spill over into other areas of life.
Unforgiveness has tentacles that will reach into your family, friendship and work relationships. You will have given the enemy the victory over your life he was looking for by offending you.
Forgiving is a life style commitment.