1 John 4:3

New American Bible - revised edition

and every spirit that does not acknowledge Jesus does not belong to God. This is the spirit of the antichrist that, as you heard, is to come, but in fact is already in the world.

Cross References

Matthew 24:5

For many will come in my name, saying, ‘I am the Messiah,’ and they will deceive many.

1 John 2:18

Children, it is the last hour; and just as you heard that the antichrist was coming, so now many antichrists have appeared. Thus we know this is the last hour.

1 John 2:22

Who is the liar? Whoever denies that Jesus is the Christ. Whoever denies the Father and the Son, this is the antichrist.

2 John 1:7

Many deceivers have gone out into the world, those who do not acknowledge Jesus Christ as coming in the flesh; such is the deceitful one and the antichrist.