What is a "Muslim" (surrendered) and what is a "Mumin" (believer/safe)?

In Islamic terminology, the terms "Muslim" and "Mu'min" have distinct meanings, each reflecting different aspects of faith and practice.

A "Muslim," derived from the root word for surrender, refers to someone who submits to the will of Allah. This is exemplified in the Qur'an where it is stated, They make it a favour unto thee (Muhammad) that they have surrendered (unto Him). Say: Deem not your Surrender a favour unto me; but Allah doth confer a favour on you, inasmuch as He hath led you to the Faith, if ye are earnest. 49:17. This verse emphasizes that the act of submitting to Allah is not merely a favor to the Prophet, but a favor from Allah to the believers who accept faith.

On the other hand, a "Mu'min" refers to a believer, someone who not only professes the faith but also embodies it through righteous actions and a deep conviction in their heart. The Qur'an describes the characteristics of true believers in Surah Al-Ahzab: Lo! men who surrender unto Allah, and women who surrender, and men who believe and women who believe... Allah hath prepared for them forgiveness and a vast reward. 33:35. This highlights that belief is accompanied by action and qualities such as truthfulness, humility, and perseverance.

From a tafsir perspective, Ibn Kathir elaborates on the concept of faith, indicating that being a believer involves not just the declaration of faith but also a commitment to righteous deeds. Similarly, Al-Mizan explains that the distinction between "Muslim" and "Mu'min" lies in the depth of faith, with "Mu'min" denoting a stronger, more complete acceptance of Allah's guidance.

In hadith literature, the Prophet Muhammad ﷺ further elaborates on these distinctions. For example, in Al-Kafi, Imam Abu Ja’far states, “A Muslim is one from whose tongue and hands other Muslims are safe,” whereas a believer is one who is an accepted trustworthy person among the Muslims in their properties and lives Al-Kafi 95:2280. This means that while all Mu'mins are Muslims, not all Muslims may fulfill the deeper obligations of faith that define a Mu'min.

In conclusion, while a Muslim is one who surrenders to Allah and follows the pillars of Islam, a Mu'min represents a higher level of faith characterized by trustworthiness, righteous action, and a sincere belief in Allah and the Last Day.