question #3 Sahih Muslim 16b, Book 1, Hadith 20 : What are the obligatory acts of worship that every Muslim must perform according to Islamic teachings?

(The superstructure of) al-Islam is raised on five (pillars), i. e. Allah (alone) should be worshipped, and (all other gods) beside Him should be (categorically) denied. Establishment of prayer, the payment of Zakat, Pilgrimage to the House, and the fast of Ramadan (are the other obligatory acts besides the belief in the oneness of Allah and denial of all other gods).