It is also an act of mercy to the community as a whole, because it increases its security. No one can claim to be more merciful to people than their Creator. Practical experience shows that over the first century of Islam, only very few hands were cut off in punishment of theft. That is because the Islamic society with its stern punishment and adequate safeguards and provisions produced only very few thieves. Allah is Much-forgiving, Merciful.
Wrongdoing is an action which is both positive and evil.
Therefore, it is not sufficient that a wrongdoer stops doing what is wrong. He should go further than that and do something which is both positive and good. In Islamic law, however, the matter goes further than that. Man is a creature who has to have something to do. If he stops doing evil without moving on to do good, he feels himself to be in a vacuum which may turn him back toward evil.