Mark 13:22

For false Christs and false prophets shall rise, and shall shew signs and wonders, to seduce, if it were possible, even the elect. For false Christs and false prophets shall rise, and shall show signs and wonders. No one can read Josephus' account of what took place before the destruction of Jerusalem without seeing how strikingly this was fulfilled.

To seduce, if it were possible, even the elect - implying that this, though all but done, will prove impossible. What a precious assurance! (Compare 2 Thessalonians 2:9.)