Repentance is the rope of Allah, and the mainstay of His concern for His servants, who must always show repentance, in every state. Each group of bondsmen has its own form of repentance:
The repentance of the prophets is for the disquiet caused to their innermost being by any outward source of vexation, while the repentance of the awliya' (friends of Allah) arises from the subtle change of hue in their thoughts. The repentance of the pure lies in their calm abandonment of whatever oppresses them; the repentance of the elite is for being occupied with anything other than Allah, and the repentance of the common people is for wrong actions. Each of them recognizes and is aware of the cause of his repentance, and his intention therein, but it would take too long to explain all of these here.
As for the repentance of the common man, he washes his inward being with the water of regret, in constant recognition of his wrong action, having regret for what he has done, and fear for what remains of his life. He does not think that his wrong actions are insignificant, for that would lead him to laziness; his continued weeping and regret for what he has missed is in itself an act of worship. He should restrain himself from his worldly appetites, and seek Allah's help in showing repentance, and to protect him from returning to what he did before. He trains himself in the arena of ignorance and worship.
He makes up for obligations missed: he answers others' calls for help, withdraws from bad company, spends his night awake, thirsts during the day, constantly reflecting on his end and seeking help from Allah, asking Him to make him steady in his states of ease and difficulty, and constant in his trials and afflictions so that he will not fall from the ranks of the repentant. This will purify him of his wrong actions, increase his knowledge, and elevate his rank. As Allah has said,
Thus Allah will certainly know those who are truthful, and Allah will certainly know the liars. (29:3)