The ruling on praying behind one who does not recite well and commits forbidden acts

Question:
May Allah reward you with good. He says: Our imam, the one we pray behind, does not recite well and commits some forbidden acts. Do we pray behind him, or do we pray on our own? May Allah reward you with good.

Answer:
If he makes a mistake in the recitation of Surat al-Fatihah that changes the meaning, such as reading "al-'alamin" instead of "al-'alamin," or reading "an'amta 'alayhim" instead of "an'amta 'alayhim," then the prayer behind him is not valid, except for one who is like him, because he disrupts a pillar of the prayer. However, if the mistake is less than that and does not change the meaning in Surat al-Fatihah, or if the mistake is in what is recited after Surat al-Fatihah, then the prayer behind him is valid, while striving to replace him with a better imam or to teach him the correct recitation. As for the sins he commits, the imam is a role model, so it is obligatory for him to be a good role model and to avoid sins. If he persists in them, it is obligatory for you to strive to replace him with a righteous imam.