The Arabic word mu’min (pl. mu’minun) is the active participle of form 4th of the root –m-n means to believe. The word mu’min thus means believer or faithful. In order to qualify as a mu’min, one must believe in the Unity of God, the finality of the Prophet, belief in God’s earliest prophets, His revealed books, His angels and the hereafter. In Koran, the attitude of true believers towards God is characterized by gratitude, awe, repentance and submission. In their attitude to their fellow humans, they are distinguished by their chastity, modesty, humility, forgiveness and truthfulness. According to the Koran, the believers are brothers (49:10), and one should assist and protect each other (8:72, 74; 9:71), peace must be established between them in case they should fight (49:9-10) and they should show each other mercy (48:29). For their belief and their righteous deeds, believers will be the recipients of God’s favour and enjoy preferential treatment, although they will be subjected to trials in this world (2:214, 3:186, 47:31). They also prosper and God makes their works succeed (2:5, 3:104, 23:1, 33:71). He strengthens the believers and defends, saves and protects them (58:22, 22:38, 39:61, 40:9). Ultimately, they will be admitted to paradise (2:25, 3:15, 9:72, 13:23, 18:31, 22:23, 23:19, 35:33, 55:54). The Koranic formula “O you who believe” (ya ayyuha lladhi amanu), which appears frequently in the chapters from the Medinan period introducing a precept or an admonition, invariably address this class of believers.
Various passages in the Koran speak of the attitude to be followed by the believers towards the unbelievers, warning them against close contacts with others who are not of their own rank. Whoever associates with them is one of them (3:28, 118; 4:144, 5:51, 9:23-4, 13:1, 60:1). The unbelievers are each other’s allies (8:73). Sitting with the unbelievers who mock the Koran is forbidden (4:140), the contributions from unbelievers may not be accepted (9:54) and praying at their graves is prohibited (9:84). Some passages explicitly forbid relations with pagan Arabs even if these are one’s own relatives. The unbeliever will only mock the believers (83:29-32) and try to corrupt them (3:99-100). One should, therefore, avoid and ignore them and pay no attention to their idle talk. Only in cases of fear for one’s life may one associate with unbelievers (3:28, 16:106). Under certain circumstances, however, it is possible to make peace with them (4:90-1, 8:61).
In short, the true believer means the composition of good qualities, sympathy and refinement. He is full of sweet odour of virtue – a living idol of piety and love. He has no filth in his mind, no flame of anger, no fire of pride, no smoke of lust and an inspirer of good deeds. Imam al-Muizz said, “The true believer is a true believer only when he has raised up a true believer like unto himself” (Cyclical Time and Ismaili Gnosis, London, 1983, p. 138 by Henry Corbin)