Belief in Allah, His Oneness and ascribing no partners to Him.
Belief in the Angels (Gabriel, Michael, Israfil, etc.).
Belief in the Qur’an and all other revealed scriptures / books (i.e. Torah, Psalms, Gospel) as in their original revealed form, not as they exist today.
Belief in Allah’s Messengers (Noah, Abraham, Moses, Jesus, Muhammad, and more).