In today's Reading 2 from Ephesians 4, Paul asked his brothers and sisters to forgive one another as God had forgiven them in Christ. To forgive is not always easy; but if we don't forgive others, we really don't have any good reason to ask God to forgive us who might have committed even worse sins. To not forgive is to not want to be like Christ, amounting to rejecting him. It is basically also being judgmental and you'll never have peace that way. Once you forgive (let go), you will feel the unburdening and experience new freedom and know that you had done the right thing. Think of forgiving others as the freeing of yourself.