3 and every spirit that doesn’t acknowledge Jesus Christ as having come in flesh is not of God; indeed, this is the spirit of the Antichrist, of which you have heard that it is coming—actually, it is already in the world right now.
1 John 4:3 Cross References - WPNT
2 Thessalonians 2:3-8
3 Don’t let anyone deceive you by any means; because that day cannot come unless the rebellion comes first and the man of sin is revealed, the son of ruin,
4 who opposes and exalts himself over everything that is called a god or an object of worship, to the point of taking his seat as God in God’s sanctuary, proclaiming himself to be God.
5 (Don’t you remember that I used to tell you these things while still with you?)
6 So now you know what is restraining, to the end that he may be revealed at his own time.
7 For the mystery of the lawlessness is already at work; only He who now restrains will do so until He removes Himself.
8 And then the lawless one will be revealed, whom the Lord will consume with the breath of His mouth and abolish by the splendor of His coming;
1 John 2:18
18 Children, it is the last hour, and just as you have heard that the Antichrist is coming, even now many antichrists have appeared, by which we know that it is the last hour.
1 John 2:22
22 Who is the liar but the one denying that Jesus is the Christ? This is the Antichrist, the one denying the Father and the Son.
2 John 1:7
7 Now many deceivers have come into the world, who do not acknowledge Jesus Christ as coming in flesh —this is the deceiver, even the Antichrist!