In verse Al Baqarah, it is explained that people who read the book of Allah that have been revealed before. They read diligently; therefore, they become stronger in faith to the book and Allah.
It is also explained that people will lost in faith if they do not follow the truth. Those people are the priests who make different interpretation toward the book.
Moslem is stipulated to believe in Allah and his revelation which has been revealed to Ibrahim, Ismail, Ishak, Yakub, Moses, Jesus, their descendant, and other profits