Islam is built upon five pillars of which fasting is the fourth coming right behind making the pilgrimage to the holy land. The first three being the shahada which is the declaration of faith, the five daily prayers and alms giving.
These feature in the famous Hadith in which the prophet was being taught about the essentials of religion by Arch Angel Jibril. During the lesson, articles of faith prominently featured; six of them to be precise.