Salam is it permissible to offer salah behind a imam whom you see committing sinful things at work place.The acts vary from not discharging their duty sincierly means taking salary for nothing to going behind female patients with wrong intentions .act clealy violating islamic teachings and then lead fardh prayers .How can i pray behind such a person but attending congregational prayer is more rewarding a big CONFUSION .The person is not ignorant of islamic teachings arabic is his language but does not refrain from such acts which are sinful should i pray alone speaking to such a person is useless he is so involved its routine for him .I see him doing such acts .I am working in health sector government employee but my colleagues most of them come late leave early disappear from work do not check the patients vital signs write all false data other non muslim staff shoulders the responsibility of their work and suffer the negligence how right is a person to do imamat what to do my soul is caught between.They do not offer sunnah just fardh when salah is suppose to change a person to do right things but same habits continue giving a wrong impression to other non muslim staff. Minor sins mistake faults do happen no one is pure.But repeating the same thing which is in our knowledge? no problem of sectism There is no sense of satisfaction

All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger.

There is no doubt that the behavior of the person whom you mentioned in the question and the people around him is contrary to the teachings of Islam. Before answering your question, we draw your attention to the fact that a person being an Arab and speaking Arabic is not enough evidence to say that he is not ignorant about the rulings of the Sharee’ah.

As regards your question, praying behind a dissolute person is valid and sufficient but it is disliked according to the view of the majority of the scholars . Indeed, the Companions prayed behind Al-Hajjaaj ibn Yoosef Ath-Thaqafi who was a very dissolute and unjust person. Anas ibn Maalik, Ibn ‘Umar and others prayed behind him.

The Fiqh Encyclopedia reads: “…The majority of the scholars are of the view that it is disliked to pray behind a dissolute person but one is not obliged to make up his prayer, as the Prophet said: “Pray behind whoever says ‘La ilaaha illa Allaah’ [None has the right to be worshipped but Allaah], and because Ibn ‘Umar used to pray behind Al-Hajjaaj, and Al-Hasan and Al-Hussein used to pray behind Marwaan (Ibn Al-Hakam) and Al-Waleed Ibn ‘Uqbah…”

There is no doubt that someone else other than that person should lead the prayer who is more suitable and eligible to be an Imaam. Ibn Taymiyyah said: “…If one person is dissolute, like him being known for lying and betraying or other similar reasons of dissoluteness, and there is another person who is a pious believer, then this second person is more eligible to be an Imaam if he can do so even if the first knows the recitation of the Quran more than him and is more knowledgeable than him, because praying behind a dissolute person is prohibited according to some scholars and is disliked according to some others. Indeed a Hadeeth reads: “A dissolute person should not lead a believer in the prayer unless he [the former] obliges him by using his whip or stick (i.e. forces him to pray behind him).” And it is not permissible to make a dissolute person as an Imaam while it is possible to appoint a pious and righteous person…”

As regards your question about whether or not it is permissible for you to pray individually, then the answer is that the congregational prayer is obligatory according to our view in Islamweb as discussed in Fatwa 82538. Therefore, it is not permissible for you to pray individually if you can pray in congregation.

Hence, we advise you to take the matter to the authorities [the people in charge] and ask them to replace this Imaam with another since he is as you mentioned. For more benefit, please refer to Fataawa 93587 and 88729.

Allaah Knows best.