Mark 13:22
For false messiahs and false prophets will appear and perform signs and wonders to deceive, if possible, even the elect — the false messiahs and false prophets will perform genuine miraculous signs — not fraudulent tricks but real displays of power. The if possible, even the elect communicates the potency of the deception: the signs are convincing enough that even the elect would be deceived if the deception were possible. The if possible implies it is not — the elect will not ultimately be deceived, but the warning is serious.