Is a person excused for their ignorance if they said it is obligatory to fulfill a Christian wife's request to go with her to church to perform polytheistic rituals, and is it incumbent upon the questioner to inform him of his error, given that he is traveling and is too shy to speak with him?

There is no basis that obliges the husband to fulfill his Christian wife's request to go to church. Some jurists, such as the Malikis, hold that he should not prevent her, while others hold that he should prevent her so as not to assist her in disbelief. This is the view of Imam Ahmad, who believes that the husband should prevent his Christian wife from going to church or to festivals, because he should not assist her in disbelief and its rituals. The view that the husband should not prevent his Christian wife from practicing her religious rituals, including her going to church, is considered valid by some scholars.