Belief in the Books of Allah implies: 1- Firm belief that all of them were revealed from Allah, 2- The Books that Allah has mentioned by name, we must believe in by name, and those which Allah has mentioned in general terms, we must believe in them in general terms, 3- Believing whatever is true of what they say, and 4- Believing that Allah revealed the Quran as a witness over these Books and to confirm them.