The six pillars of Iman (faith) are mentioned in the hadith of Jibril (AS), narrated by Umar ibn al-Khattab (RA) in Sahih Muslim:
Belief in the absolute oneness of Allah — in His existence, lordship, names and attributes, and His sole right to worship. This is Tawhid, the cornerstone of Islamic theology.
Angels are spiritual beings created from light. They never disobey Allah. Notable angels include Jibril (revelation), Mikail (sustenance), Israfil (trumpet), and Azrael (death).
Allah revealed scriptures to various prophets: the Suhuf to Ibrahim (AS), the Torah (Tawrah) to Musa (AS), the Psalms (Zabur) to Dawud (AS), the Gospel (Injil) to Isa (AS), and the Quran to Muhammad ﷺ — preserved and final.
Muslims believe in all prophets from Adam (AS) to Muhammad ﷺ. There were 124,000 prophets. Muhammad ﷺ is the final and seal of all prophets — Khatam al-Nabiyyin.
Every person will be resurrected and held accountable. Deeds will be weighed. The righteous will enter Jannah (Paradise) and the unjust will face consequences.
Everything that happens — good and bad — is by the knowledge and will of Allah. This belief brings peace, gratitude, and reliance (tawakkul) on Allah.