Many deceivers have gone out into the world; they do not confess the coming of Jesus Christ in the flesh. This is the deceiver and the antichrist. Watch yourselves so you don’t lose what we have worked for, but that you may receive a full reward. Anyone who does not remain in Christ’s teaching but goes beyond it, does not have God. The one who remains in that teaching, this one has both the Father and the Son.
2 John 1:7-9
Throughout the ages, many antichrists have come and gone. If one adds to or subtracts from the teachings of the Lord, they preach a false doctrine and endanger themselves and others of eternal damnation; do not follow them since they have departed from God! Test all teachings against the Scriptures so that the wolf does not lead you away from the flock.