Are there Bad teachers? Is Mara in the Sanga?
There have always been bad men robed as monks. If we have clear moral discernment, we will avoid them.


  
  There are many evil characters and uncontrolled men wearing the saffron robe. These wicked men will be born in states of woe because
  of their evil deeds.
  It would be better to swallow a red-hot iron ball, blazing like fire, than as an immoral and uncontrolled monk to eat the alms of the
  people.
  
  
  Dhammapada