Taqwa
Allah says: “Indeed, We commanded those who were given the Book before you, and you too, to taqwa to Allah.” (An-Nisaa: 131)
“So hold firmly to the religion which has been revealed to you.” (Az-Zukhruf: 43)
taqwa means doing what’s required and staying away from what’s forbidden.
This was Allah’s command for people before and for those after too.
(from Syajaratul Ma‘arif, Syaikh al-‘Izz bin Abdus Salam)