“For many deceivers have gone out into the world who do not confess Jesus Christ as coming in the flesh. This is a deceiver and an antichrist.”
This is a deceiver
John now stamps the person who denies the incarnation as a “deceiver” and “an antichrist.” John does not mean here that the deceivers of his day were “the” Antichrist of the Tribulation.
A “deceiver” is a religious seducer who leads others astray (1 Ti 4.1). A deceiver is an imposter, a faker, who misleads people doctrinally.
and an antichrist
An “antichrist” is someone opposed to Christ. He may usurp the role of Christ (1 Jn 2:18). The word “antichrist” occurs only five times in the Bible and all five are in John’s writings (1 Jn 2:18 [2 times], 22; 4:3).
Many fakers surreptitiously sneak into the local church with their false doctrine.
The world today is filled with phonies and fakers. Many of them are in the local church. They sneak in surreptitiously. They do not want people to know what they truly believe.
2 Pe 2: 1 “But there were also false prophets among the people, even as there will be false teachers among you, who will secretly bring in destructive heresies, even denying the Lord who bought them, and bring on themselves swift destruction.”
Ju 4 “For certain men have crept in unnoticed, who long ago were marked out for this condemnation, ungodly men, who turn the grace of our God into lewdness and deny the only Lord God and our Lord Jesus Christ.”
If a person is wrong about Jesus Christ, he is wrong about everything from God’s viewpoint. The person and work of Jesus Christ is the standard for measuring everything that matters to God. We can detect false teachers by their thinking about Christ.
Mt 22: 41 “While the Pharisees were gathered together, Jesus asked them, 42 saying, ‘What do you think about the Christ? Whose Son is He?’”
Antichristian teaching essentially is that teaching which repudiates the deity of Christ and His true humanity. If we do not honor the Son, we do not honor the Father.
Jn 5: 23 “…that all should honor the Son just as they honor the Father. He who does not honor the Son does not honor the Father who sent Him.”