How can the soul that incites to evil (An-Nafs al-Ammarah bis-Su') be purified so that it transforms into the reproaching soul (Nafs al-Lawwamah) and then into the tranquil soul (Nafs al-Mutma'innah)?

Purifying and cleansing the soul is a great objective of the Prophetic mission, and Allah has sworn by the success of whoever purifies it. Among the greatest means of purifying the soul is to hold it accountable and to oppose it in what it calls for of falsehood. The destruction of the heart comes from neglecting accountability and following whims. Ibn Al-Qayyim likened the soul to a treacherous partner; just as a partner is held accountable, so too must the soul be held accountable, beginning by stipulating with it to guard the seven limbs, then by observing and overseeing it, and then by holding it accountable upon sensing deficiency. What aids in accountability is knowing that striving in it today is rest tomorrow, and that the profit of this trade is Paradise, while its loss is the Fire. Accountability should occur before and after an action. The most harmful thing is to neglect and abandon it, which is the state of the arrogant who rely on forgiveness without accountability.