Encouraging the persistence in repentance for one who repeatedly commits a sin

Question:
A person committed a sin and resolved not to return to it, but he returned to it a second time, and a third time. He reproaches himself for it and tries to leave this sin, but he has not been able to. What do you advise him?

Answer:
In any case, it is obligatory for him to persist in repentance constantly. Allah (Exalted and Majestic is He) accepts the repentance of whoever repents. If he repents from a sin with sincere repentance, involving regret, abandoning it, and resolving not to return to it, and then he falls into it again, he is accountable for the other sin, the one he repented from... So he must strive to repent from what he fell into again.
And so, whenever he falls into it, let him hasten to sincere repentance, abandoning it, regret, and resolving not to return to it. Allah will suffice him from the evil of that sin through sincere repentance. He should ask his Lord and supplicate to Him to protect him from the evil of this sin and to shield him from the evil of his own self. He should keep the company of the righteous and leave the company of the wicked, for this is usually what causes him to return to it because of his association with the wicked who engage in this sin, such as intoxicants. If he remains in their company, he will usually return to it.
But it is obligatory for him to distance himself from the wicked, leave their company, and move to other good companions, so that perhaps he may be saved and perhaps he may be protected.
The point is: it is obligatory that he try to distance himself from the causes of returning to this sin. Otherwise, he is not held accountable for the previous sins. Every sin from which he repented with sincere repentance is erased from him. He is only held accountable for the other, new sin that he returned to. And so, and so, this is what the people of the Sunnah and the community said.