Hayom Yom: Sh'vat 19

The first positive mitzva is, in the words of Rambam,1 "To know that there is a First Being, who caused the existence of all beings...The knowledge of this principle is a positive command, as it is said, I am the Eternal your G-d."

This is a Mitzva relating to mind and intellect.* True, every one of Israel believes in G-d with a simple faith, and his heart is whole with G-d; still it is the duty of the mind and intellect to bring this faith to a level of knowledge and comprehension. This is the meaning of "To know that there is a First Being;" the Mitzva specifies comprehension and intellectual grasp, as written in Torah: "Know the G-d of your father and serve Him with a whole heart"2 and it is also written, "know this day etc."3