The Hadith of Jibril

'Umar ibn al-Khattab reported that the Companions were sitting with the Prophet ﷺ when a man appeared in brilliantly white clothes, with very black hair and no sign of travel on him, and none of them knew him. He sat close to the Prophet ﷺ and asked him about Islam, then about iman (faith), then about ihsan (excellence), then about the Hour. After he left, the Prophet ﷺ told them: that was Jibril, who came to teach you your religion (Sahih Muslim 8).

When asked about iman, the Prophet ﷺ answered: "That you believe in Allah, His angels, His Books, His Messengers, and the Last Day, and that you believe in the divine decree, its good and its bad." These six are known as the pillars of iman. The Qur'an names the same beliefs together, praising those who believe: ﴿كُلٌّ ءَامَنَ بِٱللَّهِ وَمَلَـٰٓئِكَتِهِۦ وَكُتُبِهِۦ وَرُسُلِهِۦ﴾ (“Each one has believed in Allah, His angels, His Books and His Messengers”) (2:285), and warning that whoever rejects them has gone far astray (4:136).

Islam, in the same hadith, describes the outward practice: the testimony of faith, prayer, zakat, fasting and pilgrimage. Iman describes what the heart holds true. A Muslim needs both: belief that is firm in the heart, spoken on the tongue, and shown in action. The steps that follow take each of the six pillars in turn.