The Prophet (Allah’s prayers and peace be upon him) said: “Islam is built on five (pillars): the testimony that there is no god except Allah and that Muhammad is the Messenger of Allah, establishing prayer, giving Zakat, fasting the month of Ramadan, and pilgrimage to the (Sacred) House.”

The pillars of Islam are the outward acts of worship that every Muslim must both observe and believe to be an obligation; otherwise, his belief is not valid, as Islam is built on them. That is why they are called the pillars of Islam.