Antichrist

 Here are the Bible verses which define what an Antichrist is:

2 John 1:7.   For many deceivers are entered into the world, who confess not that Jesus Christ is come in the flesh. This is a deceiver and an antichrist.

1 John 2:22   Who is a liar but he that denieth that Jesus is the Christ? He is antichrist, that denieth the Father and the Son.

1 John 4:3   And every spirit that confesseth not that Jesus Christ is come in the flesh is not of God: and this is that spirit of antichrist, whereof ye have heard that it should come; and even now already is it in the world.

More references from the kjv