Istighfar will be effective if it is serious, sincere and genuinely sought. Imagine you are faced with a major problem and you want to ask God to resolve this problem for you. For instance, a beloved person among your family or friends is facing difficulty. You have tried different methods, but you cannot resolve the problem. Now you rely on God and supplicate to Him. You know, when someone’s child or loved one is ill, for example, and they supplicate to God, how they plead for it. You should plead to God to forgive your sins in the same manner. You should repent sincerely and be determined to never again commit that sin.
It is possible that, despite determination in not recommitting a sin, a person is deviated again and repeats the sin: they should repent again. If a person breaks their repentance 100 times, again on the 101st time the door to repentance is open. However, at the time of repenting, one must not have the intention to repeat the sin and repent afterward. This is not acceptable!
A narration quotes an Imam (a.s.) as having said: “The one who repents in words, but is not regretful at heart, mocks himself/herself.” The one who repents in words (they say: may Allah forgive me), but is not regretful at heart for their sins, and is instead happy with the sins they committed, they have actually mocked themselves. This repentance is meaningless. True repentance happens when someone changes and sincerely asks God to forgive them for their wrongdoing. How is it possible for a person who aims at repeating the sin to ask God to forgive them for it?
[The leader recites a poem:]
Tasbih [rosary] at hand, repentance at the mouth, but the heart longs to commit sins!
The sin laughs at our repentance!
This repentance is nonsense! This is not sufficient. Repentance must be true and sincere.