Do priests and senior Christian clerics know that Islam is the true religion and that the Torah and the Gospel have been distorted, or do they not know, or do they know and deny, and why do they deny, and are they convinced of Islam?

Not everyone who seeks the truth attains it, and not everyone who knows it follows it. Rather, many who know it reject it out of arrogance, denial, envy, or preference for worldly life. The Quran has mentioned that arrogance, envy, and the desire for leadership are among the reasons for rejecting the truth after knowing it, citing verses from Surahs Ghafir, Fatir, Al-Baqarah, and At-Tawbah (definition). It clarifies that the People of the Book knew the truth but concealed it and turned away from it, seeking worldly leaderships and out of envy.