"Whoever has No Shyness has nothing of humanity left with them, except for flesh and blood..." -Ibn al-Qayyim

Shame, shyness and modesty prevent a person from that which is unbefitting and wrong. The one whom Allah has blessed and nourished with modesty and shyness is prevented from vile behaviour and evil conduct― and he is distinguished with fine attributes and feels shy to commit indiscretions against His Lord. Modesty and shyness, therefore, is good and its absence is a deficiency and shortcoming. The Prophet (ﷺ) said:

إِنَّ مِمَّا أَدْرَكَ النَّاسُ مِنْ كَلاَمِ النُّبُوَّةِ الأُولَى إِذَا لَمْ تَسْتَحِي فَاصْنَعْ مَا شِئْتَ

“From the sayings of the early Prophets which has reached the people is: ‘If you have no sense of shame or modesty, then do as you please!" (SahiAl-Bukhari).

This proves that the one who loses his sense of shame and modesty will end up doing whatever he wants of evil, lowly, shameless and reprehensible deeds. So the narration shows that actions are from Imān because of the fact that modesty and shyness is an action of the heart, and it is a branch from the branches of Iman. The Messenger of Allah (ﷺ) stated:

الإِيمَانُ بِضْعٌ وَسِتُّونَ شُعْبَةً، وَالْحَيَاءُ شُعْبَةٌ مِنَ الإِيمَانِ

“Iman is sixty and odd branches―and having a sense of shame and modesty (Al-Haya) is from Iman.” (Sahi Al-Bukhari)

So one who has little shame and little modesty also has little Iman―and the one who has no shame whatsoever, then his or her Iman is hugely deficient.