23 Shevat 5777
"The erev rav is that part of the Jewish People intent on war against God and against the truth and credibility of His Torah..."
Make no mistake. Many of them wear a kippah and some are even called "Rabbi". But, they bring another Torah - one more pleasing to their own sensibilities - to replace the one we received at Har Sinai.
The only way to tell who they really are is to listen closely to what they say. Some are more obvious than others. Some stay very close to the truth and only deviate in ways which can easily confuse unlearned people. But, once they have convinced you to follow them down their deviant path, the longer you go, the further from the truth you are until you are completely corrupted.
"...With them we face an uncompromising battle to the finish, [a war for hearts and minds] and the Gra emphasized this in his call to holy war against them. When he says that whoever does not actively fight the erev rav becomes their partner and is better off never having been born, he means to warn against the distorted tolerance and groundless love which are the main impediments in this war." (Source)
See also "The Loyalty Phenomenon" Indeed.