Does sin befall someone who directs a person to the location of an innovative Sufi mosque that contains a grave, while being unaware of the questioner's intention? And what should be done in the future when encountering places of iniquity?

Prayer is not permissible in mosques that contain graves. If the questioner believes that the person inquiring about the mosque intends to pray there, it is not permissible to direct him to it, as this constitutes aiding in sin. Instead, one should advise him and explain the ruling on praying in such mosques. This applies to every reprehensible act; guiding someone to it is aiding in sin. Allah Almighty says: "And cooperate in righteousness and piety, but do not cooperate in sin and aggression."