If we don’t forgive others, we are being inconsistent with our belief system as Christians. If we really believe in His salvation, we realize that we have broken God’s law and needed forgiveness. When we come to God in faith, He will change our hearts and after that we will desire forgive others. If we refuse to have a forgiving heart, then our heart has not been changed. It proves that we don’t believe in God’s forgiveness. I believe that people who try to accept Jesus’ forgiveness and refuse to forgive others, really don’t believe they sinned much in the first place. Perhaps they believe that they are good enough to be forgiven. When they are faced with obeying the law from their hearts and forgiving others who have sinned, they show what they really have on the inside. We cannot come to God without believing in the fact that we are sinners and needed forgiveness.
Romans 13:19-22a :
Now we know that whatever things the law says, it speaks to those who are under the law, that every mouth may be closed, and all the world may be brought under the judgment of God. Because by the works of the law, no flesh will be justified in his sight. For through the law comes the knowledge of sin. But now apart from the law, a righteousness of God has been revealed, being testified by the law and the prophets; even the righteousness of God through faith in Jesus Christ to all and on all those who believe.
The problem with legal relationships is that they don’t change the heart, they only expose the truth about your heart. We do need exposure, but what we really need is a way to actually live the way that the law demands and that is what Jesus brought us by His death and resurrection. He followed the laws for us; He forgive everyone who sinned against Him including us. Isn’t that amazing? That is what grace is and it is the realization of this grace and the power that comes from God that makes us willing and able to forgive others.