Is it permissible for a man who watches pornographic films and is dishonest with his friends to give a lesson, or a sermon, or make the call to prayer (adhan), or lead people in prayer (imamate)?

The duty is to advise this man secretly if you are certain he has committed a sin, and not to expose him or spy on him, as suspicion of a Muslim, spying, and backbiting are forbidden. If it is proven that he is afflicted with these matters, then it is not appropriate to receive knowledge from him or to appoint him as an Imam or Muezzin, unless he repents. It is obligatory to search for a righteous person for Imamat, Adhan, and lessons, because the Imam and Muezzin are entrusted. Wisdom should be observed in rebuking him.