Sin is the origin of man’s problem. When God created the first humans; Adam and eve, things were going on well according to God's plan. But the moment they sinned through disobedience, problems set in and since then, the world has been full of sins.
But for us to live a meaningful life, sin has to be forgiven and forgotten. Master Jesus was badly persecuted, yet he forgave his persecutors as recorded in Luke 23:34 showing the importance of forgiveness of sin.
Sin is a bitter experience, but we should try as much as possible to forgive because it is necessary we do so. I encourage you to forgive your offenders so as to create an atmosphere of peace when you live peacefully with your fellow human beings, you’ll gain a lot and the world will be a peaceful place to live in .
Remember that you too can sin against another because you are not perfect and at such times you will need forgiveness too.
To this end, it is important, we forgive one another.