What is the ruling on a Muslim reading some books of the Jews and Christians—for someone who grew up Christian—given the presence of doubts concerning the texts that describe the prophets?

Every Muslim is advised to thank Allah for the blessing of faith and to utilize time in beneficial knowledge and righteous deeds, because life is short and does not suffice for all of that. Focus should be on good deeds, not on that which is useless, such as reading the Torah and the Gospel for those who are not specialized. For "from the moment a servant's foot is firmly placed in this abode, he is a traveler therein to his Lord, and the duration of his journey is the lifespan decreed for him." As for religious specialists and researchers, they are permitted to read these books to fulfill fard al-kifaya (a collective obligation) and to refute opponents, provided they are firmly grounded in knowledge and that they present what they read to the Quran and Sunnah.