Surely Allah is not ashamed to set forth any parable-- (that of) a gnat or any thing above that; then as for those who believe, they know that it is the truth from their Lord, and as for those who disbelieve, they say: What is it that Allah means by this parable: He causes many to err by it and many He leads aright by it! but He does not cause to err by it (any) except the transgressors,

And when Allah said: O Isa, I am going to terminate the period of your stay (on earth) and cause you to ascend unto Me and purify you of those who disbelieve and make those who follow you above those who disbelieve to the day of resurrection; then to Me shall be your return, so l will decide between you concerning that in which you differed.