Must a wife refrain from conjugal relations with her husband if she fears he has committed an act that would lead to disbelief (kufr), knowing that she is not qualified to declare him an unbeliever?

It is not permissible for the wife to build a judgment on doubts, for the basic principle regarding a Muslim is innocence, and one whose Islam has been established with certainty does not lose it except with certainty. Therefore, the wife should not pay attention to these doubts and should beware of obsessive whispers (waswasah). She must live with her husband in kindness, and if she sees him doing something that violates Islamic law, she should enjoin him to good and forbid him from evil.