As understood from the teachings of Hakim al-Umma Mawlana Ashraf Ali Thanavi (Allah have mercy on him) under Shaikh Mufti Taqi Usmani’s (Allah preserve him) guidance ,
Islah is the betterment or reformation or change of heart (dil badalna) in such a way that the commands of Shariah are followed both in external and internal acts of worship to the best of one’s ability. This is essentially accompanied with acknowledgment of one’s severe short comings in trying to do so.
The real islah is that of the actions of the heart (amal e batini) first and then the outwardly actions that are produced physically are rectified. It is usually not the other way around. This is as mention in the blessed Prophetic saying (hadith of qalb).
The initiating foundation stone of islah is a flash of Divine attraction (jazab) that is bestowed on the selected individual. Its outwardly reason maybe reading something touching, attending a pious individual or place, dua of parents, shaikh etc. In reality it is a kind gift (fadhal o karam) of Allah alone. Everyone of us has to beg for this fadhal e adheem ardently in his/her dua. If the individual is really blessed then he/she will try to safeguard the effects of this Divine attraction by reforming his/her (dhari o batini) actions. If he/she is careless then this will fade away and even might not return ever. Allah save us from this deprivation. Amin!
Tasawwuf provides a frame work for developing this islah. The components of Tasawwuf, like one-to-one mentor-ship, discipline, regular routine, wird, pious gathering and recommended readings all act as catalyst in this growth of islah. However, the real things needed to do the chemical reaction of islah are the firm determination and sincere effort of the salik him/herself.
Catalyst alone can not do the reaction.
Bayah is not essential for islah. It is highly discouraged to be hasty in selecting a Shaikh.
The special nights of Ramadan, Eid, the blessed days of Zil-Hajj, etc. are ideal for asking for this fadhal e adheem of Allah.
Darul Uloom, Karachi