Original Verse:
1st John Chapter 4 Verse 3And 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.

Reference Verses:
1st John Chapter 2 Verse 18Little children, it is the last time: and as ye have heard that antichrist shall come, even now are there many antichrists; whereby we know that it is the last time.
2nd John Chapter 1 Verse 7For 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.
2nd Thessalonians Chapter 2 Verse 7For the mystery of iniquity doth already work: only he who now letteth will let, until he be taken out of the way.
2nd Thessalonians Chapter 2 Verse 8And then shall that Wicked be revealed, whom the Lord shall consume with the spirit of his mouth, and shall destroy with the brightness of his coming:
1st John Chapter 2 Verse 22Who is a liar but he that denieth that Jesus is the Christ? He is antichrist, that denieth the Father and the Son.