An-Nisa 4:159

Wa-in min ahli alkitabi illalayu/minanna bihi qabla mawtihi wayawma alqiyamati yakoonuAAalayhim shaheeda

And there is none from the People of the Scripture but that he will surely believe in him [i.e., Jesus] before his death. And on the Day of Resurrection he will be against them a witness.

No one will remain from among the People of the Book but will certainly believe in him before he dies, and on the Day of Doom, he shall be a witness against them.