creed / belief system / doctrine
Feminine noun. From عَقَدَ (to tie/bind). Literally 'that which is firmly tied/bound in the heart.' The six articles of faith are the core ʿaqīdah.
ʿAqīdah encompasses the six pillars of faith: belief in God, angels, scriptures, messengers, the Last Day, and divine decree - the theological foundation of Islam.