Jesus was warning his followers then and now to be wide awake and alert to false teachings.
He also said: “Be on the watch for the false prophets that come to you in sheep’s covering, but inside they are ravenous wolves.” (Matt. 7:15) Watchfulness and caution are therefore essential to avoid becoming prey to greedy, wolfish men.
Also the apostle Paul under inspiration declared: “I know that after my going away oppressive wolves will enter in among you and will not treat the flock with tenderness, and from among you yourselves men will rise and speak twisted things to draw away the disciples after themselves.” And Peter, an apostle of Jesus Christ, also spoke of this peril: “There will also be false teachers among you. These very ones will quietly bring in destructive sects and will disown even the owner that bought them .*.*. Also, with covetousness they will exploit you with counterfeit words.”
The apostle Paul disclosed two giveaway signs of deception, namely, a twisting of the words of truth and a lack of the spirit of tender affection.
Peter speaks of counterfeit words and the promotion of sects, groups following men.
Jude intimates that a departure from the high moral standards of the Bible would be a danger signal.
John points to a denial of the true relationship existing between the heavenly Father and his Son, Christ Jesus, as another indication of antichristian deception.
(1 John 2:22) Who is the liar if it is not the one that denies that Jesus is the Christ? This is the antichrist, the one that denies the Father and the Son.