As Salaam Alaykum Sheikh. May Allah azza wa jalla honor you, your family and the SOK team. My question is (forgive my ignorance) I don't understand how Sheikh Al Islam ibn AbdulWahab came to the conclusion that knowledge is to know Allah SWT, the prophet SAW and Islam in usūl ath-Thalātha.

These three are what everybody will be asked about in his grave: who is your Rabb (Lord), what is your religion, and who is your Prophet. The scholars said these three foundations gather the whole religion. And what is the religion other than knowing Allah and worshipping him by the religion He Legislated by following the example of the Prophet he sent