A story told by one of our elders during members’ class. Of course, all illustrations have their limits but this is very helpful:
Pretend that someone came into my house and killed my only son. If as he was fleeing, I took a shotgun and chased him down and killed him, we would call it revenge. If, [however] I called the police and they arrested him and he was sent to prison, we would call it justice. If I went to the jail and told him I forgave him and did not hold anything against him, we would call it mercy. If I forgave him and got him out of jail and took him home and adopted him into my family and he became my son with all the privileges of sonship and full inheritance rights, we would call it grace. That is exactly what our Lord did. We killed His son and yet He forgives us and adopts us into His family with full inheritance rights. Amazing grace!