What is the ruling on praying behind an imam who is disobedient or an open sinner?

Question:
In another letter sent by one of the listeners, he asks: What is the ruling on praying behind one who commits some sins? And what is the ruling on the prayer of the followers in this state?

Answer:
It is obligatory that the imam be in the best state of uprightness, distance from sins, and engagement in acts of obedience and noble character; because he is a role model. However, infallibility is not attainable for everyone except the Messenger (peace and blessings be upon him). A person may fall into sins, but the door of repentance is open. If one repents, Allah accepts his repentance, whether he is an imam or anyone else. And whoever repents from a sin is like one who has no sin. As for one who commits sins, persists in them, and displays them openly, he should not be appointed as an imam, because people follow his example. The apparent sins that people see him committing, such as letting the garment hang below the ankles, shaving the beard, smoking, and other sins, or if they are major sins like drinking intoxicants or the like, then he is not fit for the imamate, because he becomes a role model and a caller to sins. There is scholarly disagreement among the people of knowledge regarding the validity of praying behind an open sinner: is it valid or not? This indicates the seriousness of the matter and the difficulty of this issue, and that one should not be lenient in it, because the imam is a role model and must be in the best possible state. Yes.