Persisting in sin

Firstly: 

If a person
commits sin time after time, his sin is forgiven every time if he follows
his sin with repentance – if his repentance each time is sincere. The
evidence that it is permissible to repent time after time is the fact that
those who apostatized from Islam at the time of Abu Bakr were brought back
to Islam by Abu Bakr and he accepted that from them, although he knew that
they had been kaafirs, then they entered Islam, then they went back to kufr,
then they came back to Islam. All the Sahaabah accepted their repentance
despite the fact that what the apostates had done was worse than what a
sinning Muslim does. So the repentance of a sinning Muslim, even if he sins
repeatedly, is more likely to be accepted than repentance on the part of a
kaafir time after time.  

But what we
are saying is subject to the condition that the first and subsequent cases
of repentance be sincere and from the heart, not simply an outward show of
repentance. 

What we are
saying should not be understood to mean that we are encouraging sin and that
it may be committed time after time, and that the Muslim should take the
mercy of Allaah and the fact that Allaah accepts repentance as an excuse to
commit sin. No, our intention is to encourage the sinner to repent time
after time. We want to put the mind of the Muslim who wants to come back to
Allaah at rest, and tell him that the gate of mercy is open, and that
Allaah’s forgiveness is greater than his sin, so he should not despair of
the mercy of Allaah and he should keep turning to Him. 

Al-Bukhaari
(7507) and Muslim (2758) narrated from Abu Hurayrah that the Prophet
(peace and blessings of Allaah be upon him) said that his Lord said: “My
slave commits sin, then he says, ‘O Allaah, forgive me my sin.’ Then Allaah
says, ‘My slave has committed a sin, but he knows that he has a Lord Who
forgives sin and takes away sin. So I forgive My slave.’ Then he commits sin
again, and says, ‘O Allaah, forgive me my sin.’ Then Allaah says, ‘My slave
has committed a sin, but he knows that he has a Lord Who forgives sin and
takes away sin. So I forgive My slave.’ Then he commits sin again, and says,
‘O Allaah, forgive me my sin.’ Then Allaah says, ‘My slave has committed a
sin, but he knows that he has a Lord Who forgives sin and takes away sin. So
I forgive My slave.’ …” 

Al-Haafiz
Ibn Rajab al-Hanbali said: 

Ibn Abi
Dunya narrated with his isnaad that ‘Ali said: “The best of you is every
tempted one who repents (i.e., every time he is tempted by this world, he
repents).” It was said, “What if he sins again?” He said, “He should ask
Allaah for forgiveness and repent.” It was said, “What if he sins again?” He
said, “He should ask Allaah for forgiveness and repent.” It was said, “What
if he sins again?” He said, “He should ask Allaah for forgiveness and
repent.” It was said, “For how long?” He said, “Until the Shaytaan is
defeated.” 

Ibn Maajah
narrated a marfoo’ report from Ibn Mas’ood which says: “The one who repents
from sin is like the one who did not commit sin.” (Classed as hasan by
al-Albaani in Saheeh Ibn Maajah, 3427). 

It was said
to al-Hasan: Shouldn’t one of us feel too shy to ask his Lord to forgive his
sin, then do it again, then ask for forgiveness, then do it again? He said:
The Shaytaan wishes that you would have this attitude, so do not tire of
asking for forgiveness. 

And it was
narrated that he said: I do not think this is anything other than the
attitude of the believers, i.e., every time a believer sins, he repents. 

‘Umar ibn
‘Abd al-‘Azeez said in his khutbah: O people, whoever commits sin, let him
seek the forgiveness of Allah and repent. If he does it again, let him seek
the forgiveness of Allah and repent, and if he does it again, let him seek
the forgiveness of Allah and repent. For it is sin which hangs around a
person’s neck, and doom comes from persisting in sin. 

What this
means is that a person will inevitably commit the sins that it is decreed he
will commit, as the Prophet (peace and blessings of Allaah be upon him)
said: “Every son of Adam has his share of zina (adultery) written for him,
and that will inevitably catch up with him.” (Narrated by Muslim, 2657). 

But Allaah
has given people a way out from the sins they commit and sin is erased by repentance and seeking forgiveness. If they do that then they will get rid of the evil of sin, but if they persist in sin, then they will be doomed. 

Jaami’ al-‘Uloom wa’l-Hakam, 1/164-165. 

And Allaah knows best.