Modesty is part of Iman (faith).
The Book of Faith - Sahih Muslim 36 a
The hadith "Modesty is part of Iman (faith)" from Sahih Muslim establishes a fundamental connection between moral character and true faith. Classical scholars explain that modesty (al-hayā') serves as both an indicator and protector of faith.
The Nature of Modesty in Islam
Imam al-Nawawi comments that modesty is a quality that prevents one from committing disgraceful acts and abandoning duties. It manifests as restraint from what is reprehensible and as dignity in conduct.
Ibn Rajab al-Hanbali elaborates that modesty is of two types: innate modesty that Allah places in every person, and acquired modesty through knowledge of Allah and His majesty.
The Relationship Between Modesty and Faith
Scholars explain that modesty cannot exist without faith, nor can faith be complete without modesty. They are interdependent - as faith increases, modesty strengthens, and as modesty decreases, faith weakens.
Al-Qurtubi states that modesty is the characteristic that most frequently leads to obedience and prevents disobedience, making it an essential component of living faith.
Practical Manifestations
This modesty manifests in: modesty before Allah regarding what He has prohibited, modesty before angels who record deeds, and modesty before people in social interactions.
True modesty, according to classical scholars, leads one to fulfill obligations, avoid prohibitions, and maintain excellence in character - all essential aspects of complete faith.