What is the ruling on praying behind an Imam who performs qunut in the Fajr prayer while believing it to be an innovation, and is it obligatory to follow him in the qunut and raising the hands, and what should the worshipper do if the Imam performs the prostration of forgetfulness (sujud al-sahw) for forgetting the qunut, and is it permissible to pray behind an Imam who believes that qunut is a Sunnah?

Muslims must adhere to the Qur'an and Sunnah (definition) and abandon fanaticism towards imams and scholars. The issue of Qunut in Fajr prayer is disputed, and the correct view is that it is not a perpetual Sunnah unless there is a calamity. If the imam performs Qunut in Fajr, then he should be followed to promote unity and solidarity. Your prayer behind him is valid even if he differs from what you consider correct, unless his action would invalidate his own prayer. The follower should follow his imam in matters of ijtihad (definition) (independent reasoning), and there should be no hesitation in praying behind someone who differs with you on such issues. If the the imam forgets the Qunut and performs the prostration of forgetfulness (sujud (definition) as-sahw), he must be followed.