Who is the liar but he who denies that Jesus is the Christ? This is the Antichrist, he who denies the Father and the Son.

 2:19-21 They have gone out from among us but they are not of our number. If they had been of our number, they would have remained with us. But things have happened as they have happened, that it may be clearly demonstrated that all of them are not of us. But you have received anointing from the Holy One and you all possess knowledge. I have not written this letter to you because you do not know the truth, but because you do know it and because no lie comes from the truth. 