Question: I learnt from the Abhidhamma that remorse is an unwholesome mental factor. If so, why do we chant Repentance Verses?
Answer: ‘Remorse’ (Kukkucca) is deemed unwholesome only when it is as below, in terms of (1) regret over good undone, and (2) regret over evil done. It hinders spiritual practice as it causes fretful restlessness. When we chant the Repentance Verses, it is exactly to overcome or rid this remorse, so as to regain peace of mind for furthering steady spiritual practice. Not having regret over evil done is in fact ‘moral shamelessness’ (Ahirika), that leads to doing of more evil due to lack of shame. The practice of repentance is to recognise evils done and to express resolution to never do them again. It does not nurse regrets with no resolution. It is thus a crucial practice.
From p.120 & 116 of www.buddhanet.net/pdf_file/abhidhamma.pdf :
Kukkucca (Remorse):
‘… Remorse over the evil that is done is Kukkucca, and so is remorse over the good that is not done. It has the characteristic of grieving over the evil that is done and the good that is not done… Kukkucca is one of the Five Hindrances (which hinder spiritual progress: sense desires, ill will, sloth and torpor, restlessness and doubt) and is used together with Uddhacca (Restlessness). It pertains to past things only.’
Ahirika (Moral Shamelessness):
‘… He who is not ashamed of doing evil is Ahiriko (shameless)… One who has Hiri (shame) recoils from evil just as a cock’s feather shrinks in front of fire. One who has no Hiri (Shame), would commit any evil without the least compunction.’