Allah, ta^ala, said in the Qur’an:

[ أفي الله شكّ ]

Ayah 10 of Surah Ibrahim means: {There is no doubt about the existence of Allah.}

The first obligation on the mukallaf person is to know about Allah, ta^ala. Allah is the Creator of all the existent things and is the One Who manages all the creation. If, with our sound mind, we carefully think about all the creations and ponder about their existence, we must know that they have a Creator Who created them.