We all make mistakes. So when we learn to forgive others, we can also seek forgiveness when we commit follies. Also if we are able to forgive others, we also learn to forgive ourselves in situations of self-guilt. Thus the virtue of forgiveness helps us come out of the feeling of self blame. If we fail to forgive ourselves in time, we often end up realizing that others had forgiven us long back, but we kept feeling bad about ourselves all this time.
Forgiveness helps us feel light and helps us get rid of hard feelings that occupy our mind and heart and eat away our peace of mind. Forgiveness is a way to self-fulfillment. People who can readily forgive others are much more responsible and satisfied inside than those who keep grudges against others and develop feelings of enmity. The feeling of anguish only results in arguments, fights, mistreatments and war in certain cases. Those who forgive help create positive energy on this planet.
Now, let us take the example of a terrorist who kills hundreds of innocent people in a terrorist attack. Does he deserve forgiveness? Such criminals kill common man in the name of religion and consider it a way to please or reach their God. Heinous Acts of this degree do not deserve mercy and forgiveness. Though there may be people who would still believe that forgiveness is humanity, yet to discourage and prevent any such future acts of terrorism, such people must be severely punished and not forgiven.
If the people who are close to you betray or hurt you, you find it most difficult to forgive them. Sometimes the extent to which your trust is breached determines the ease or difficulty in forgiving. But it is true that the more easily we forgive the other person, the less likely we shall suffocate ourselves keeping bad intentions for the wrongdoer. We need to feed it into our system to let go so that we do not stay annoyed and offended for long. Our grudges will only affect the relationship with the person and not hurt the other person in any way. The ability to forgive gives us a sense of freedom and makes us suffer less and feel lesser misery and pain.