Shaykh Ibn Baz explains that the word "Islam" itself means to submit to Allah with Tawhid (monotheism), to yield to Him in obedience, and to disavow shirk (polytheism) and its people. It is the religion of all prophets, from Adam to Muhammad (peace be upon them all), culminating in the final message brought by the Prophet Muhammad ﷺ.

The foundation of a Muslim's belief is detailed in the famous Hadith of Jibril, where the Angel Jibril (Gabriel) appeared in the form of a man and questioned the Prophet ﷺ about the religion. These beliefs are known as the Six Pillars of Iman (Faith):

1. Belief in Allah: To believe in His existence, His lordship (Rububiyyah), His right to be worshipped alone (Uluhiyyah), and in His unique names and attributes (Al-Asma’ was-Sifat) without distortion, denial, questioning, or comparison.
2. Belief in His Angels: Created beings of light who act as His messengers and carry out His commands.
3. Belief in His Books: The divine scriptures revealed to His messengers, such as the Torah, the Gospel, and the final and uncorrupted scripture, the Qur’an.
4. Belief in His Messengers: Men chosen by Allah to convey His message, ending with the final prophet, Muhammad ﷺ.
5. Belief in the Last Day: The Day of Judgment, when all humanity will be resurrected to be held accountable for their deeds, leading to an eternal life in Paradise or Hellfire.
6. Belief in the Divine Decree (Al-Qadar): That Allah has knowledge of, has recorded, and has willed everything that happens, both good and bad.

These beliefs are put into practice through the Five Pillars of Islam: the testimony of faith (Shahadah), establishing prayer (Salah), giving obligatory charity (Zakat), fasting in Ramadan (Sawm), and making the pilgrimage to Makkah (Hajj) for those who are able.