يا أيها الذين آمنوا توبوا إلى الله توبة نصوحا
O you who believe! Turn to Allah a sincere repentance.
As for sincerity in repentance, it is achieved when a repentant abandons sin for the sake of Allah alone. Seeking His forgiveness and seeking His favor and escaping His punishment as opposed to abandoning sin for a worldly reason. Examples of giving up sins for worldly reasons are giving up smoking or drinking because of fear for one's health or a drug dealer giving up this sin because of fear of imprisonment or because of his reputation. A penitent who leaves a sin for the sake of Allah, the Most High, repents sincerely to Him, and he who leaves it for other than Allah is not sincere in his repentance.
Among the most helpful ways to achieve sincere repentance are: keeping the company of righteous people and distancing oneself from bad companions. Staying away from places that remind a repentant of sins or where he would be vulnerable to sin is another helpful means. In the story of the man who killed 99 people, he was commanded to leave his town and move to another one where righteous people lived.
Allah (SWT) says,
"Turn towards Allah, O believers, every one of you, so that you may be successful." - 24:31
"Ask your Lord for forgiveness and then turn in repentance to Him," - 11:3
"O you who believe! Turn in sincere repentance to Allah." - 66:8
Rasulullah (Sallallahu alaihi wasallam) said,
'The one who repents from sin is like the one who never sinned.' - Ibn Maja (3240)
'Remorse is repentance.' - Ibn Maja (4242) and Ahmad (3387)
Abu Huraira reported that Rasulullah (Sallallahu alaihi wasallam) said, "Allah will turn towards anyone who turns in repentance before the sun rises from the place it set." - Muslim
Imam Barkawi, the great Ottoman Hanafi faqih, grammarian, and sufi, defined repentance (tawba) in his Tariqa al-Muhammadiyya as, "Going back from desire to sin, with the determination of not returning to it, in exaltation of Allah and out of fear of His punishment." - al-Bariqa fi Sharh al-Tariqa, 3.139
The Conditions for Repentance
- Leaving the sin
- Remorse over having committed the sin
- Resolve never to return to the sin
If the sin relates to the rights of another person, then to Return the rights or property one wrongly took.
If these conditions are truly met, then one can expect one's sins to be forgiven. However, one has to be very careful about how sincere one is in fulfilling one's conditions. It is recommended to seek forgiveness a lot, and to repent every time the sin comes to one's mind.
If one keeps repeating the sin, then one should find the root cause(s) of the sin and eliminate them. For example, if one falls into a certain sin because of the company one keeps, then it would be necessary to either stop keeping their company, or to change the nature of one's relationship with them.
And Allah knows best