Beliefs are very important in Islam. To be considered a Muslim, one must believe and recite a statement of faith known as the Shahada: "There is no God but God, and Muhammad is his Prophet."
There is no other official creed to which one must adhere to be considered a Muslim. However, the "Six Articles of Faith" summarizes Islamic beliefs about God, angels, prophets, the Qu'ran, the afterlife, and predestination.