One of the teachings of Islam-and indeed of all religions of heavenly origin-is that sinners always have the possibility of repentance before them. When a man is genuinely remorseful in regard to his sins, and his spirit turns him towards God in humility, and with a pure heart he resolves never to repeat his sins, then God, who is infinitely kind, accepts his repentance. The Qur'an says:
Those who are unaware of the reforming influence of repentance and the belief in intercession imagine that opening up these two doors for sinners is a kind of invitation to them to commit sin! Those who think thus seem to be oblivious to the fact that many people are, in different ways, besmirched with some sin; rarely can one find a person who, throughout his life, has never sinned. Who, indeed, has never sinned in this world? Therefore, if the door of repentance (and of intercession) Were not open, those souls who might be ready to renounce a life of sin and to resolve, henceforth, to lead lives of purity and goodness-such people would say to themselves: 'We shall have to endure the punishment of Hell because of the sins we have committed; so why not spend the rest of our lives gratifying our souls' desires and losing ourselves more completely in the bosom of illicit pleasure?' In this way, the closing of the door of repentance opens wide the entrance of the pit of despair as regards the mercy of God; behaviour will then follow the downward path of concupiscent desire, rather than the upward path of fervent hope.
The positive effects of the principle of repentance become dearer when we understand that the acceptance of repentance in Islam requires the fulfilment of certain conditions, as the sages and the scholars of our religion have explained. The most important such condition is that one determines to no longer perform the sins of which one repents. The Qur'an says clearly and explicitly, as regards the door of repentance: