In order to receive the forgiveness of our sins, we must forgive others. Forgiving others allows us to overcome feelings of anger, bitterness or revenge. Forgiveness can heal spiritual wounds and bring peace and love that only God can give.
Forgiveness is not a feeling, it is a choice, an act of our will. If we wait until we feel willing to forgive, we will never forgive. We should not let ourselves be guided by our emotions but rather choose to obey. Then, over time, God will make our emotions correspond to the correct decision we have made.
Secondly, God commands us to forgive, no matter how we feel and regardless of what they have done to us.
Jesus says in Mark 11:25, "And when you are praying, if you have something against someone, forgive him, so that also your Father in heaven will forgive you your sins." Before praying, if you have something against someone, (there is a step you should take first): Sorry. Jesus says we have to do this so that our Heavenly Father will forgive our sins.
As infinite, unconditional and great as His forgiveness for us is, it must be the measure of forgiveness we extend to others. People who are not truly Christian do not have the capacity to forgive, since they have never experienced God's love and forgiveness. But if you are a child of God, if you have been washed by the blood of Jesus, if you have experienced His forgiveness, then you can extend that same forgiveness to others.
"When we forgive, we are not changing the past, but the future. "
Do not judge, and you will not be judged. Do not condemn, and you will not be condemned. Forgive, and they will be forgiven.Lucas 6:37