Is it permissible to pray behind mosque imams who are ignorant of the issue of excommunicating those who revile the Divine Essence, the Messenger, and the Companions, and what should I do to preserve my religion in a society where such phenomena are prevalent?

What has been mentioned are grave abominations. And whoever is afflicted with living in such societies must strive diligently, with wisdom and knowledge, to rectify this corruption. Most likely, this phenomenon stems from ignorance of the rulings of Islamic law, as Allah Almighty says: "And if you ask them, they will surely say, 'We were only jesting and playing.' Say, 'Is it Allah and His verses and His Messenger that you were mocking?' Make no excuse; you have disbelieved after your belief." The duty of enlightening people about matters of faith falls upon the خطباء (preachers) and imams of the mosques. As for praying behind such individuals, it is valid. It is advised to frequently recite the Book of Allah, to gain deep understanding of the Sunnah, and to seek righteous companionship.