What is the ruling on praying behind an Imam who commits an act forbidden outside the prayer, such as marrying without a guardian or consuming a small amount of *nabidh* (fermented drink), based on his own belief?

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If the Imam persistently commits an act he believes to be forbidden in matters external to the prayer, such as marrying without a guardian (if he believes this invalidates the marriage) or consuming a small amount of *nabidh* (if he believes it forbidden), he is considered a transgressor (*faslq*), and his status is the same as other transgressors. If he does not persist in this act, there is no issue in praying behind him, as such acts are considered minor sins (*sagha'ir*). If the performer of such an act is a layman (*a'ami*) who is merely following a scholar whose opinion he believes permits the act, there is no blame upon him, as the duty of a layman is to ask the people of knowledge and follow them, according to the command: {Ask the people of remembrance, if you do not know} (Quran 21:7).