We know Allah through Tauhid, which means that we worship only Allah and don't assign partners to him (Shirk شرك).

(Tawḥīd ar-Rubūbiyya توحيد الربوبية)

Allah alone is the Lord of everything, he is the giver of life and death and he controls everything.

(Tawḥīd al-ʾUlūhiyya توحيد الألوهية)

All types of worship like prayer, fasting, pilgrimage, supplication (Du'a دعاء) must be directed exclusively to Allah.

“And I did not create the jinn and mankind except to worship Me.” (Surah 51:56)

(Tawḥīd al-ʾAsmāʾ wa-ṣ-Ṣifāt توحيد الأسماء والصفات)

We believe in Allahs names and attributes exactly as he described himself in the Quran and Sunnah

“Vision does not perceive Him, but He perceives [all] vision.” (Surah 6:103)