1 John 2:18-21

18 Little children, it is the last hour; and as you were given word that the Antichrist would come, so now a number of Antichrists have come to you; and by this we are certain that it is the last hour.

19 They went out from us but they were not of us; if they had been of us they would still be with us: but they went out from us so that it might be made clear that they were not of us.

20 And you have the Spirit from the Holy One and you all have knowledge.

21 I have not sent you this letter because you have no knowledge of what is true, but because you have knowledge, and because that which is false has nothing in common with that which is true.