# For many deceivers have gone out into the world

"For many false teachers have left the congregation" or "For many deceivers are in the world"

# many deceivers

"many false teachers" or "many imposters"

# Jesus Christ came in the flesh

"Jesus Christ came as a real human" 

# This is the deceiver and the antichrist

"They are the ones who deceive others and oppose Christ himself"