Is a man considered an infidel if he asks his Christian wife to swear "by Jesus" to believe him, and he does not intend by that to glorify our Master Jesus more than glorifying God?

It is not permissible to swear by anyone other than Allah Almighty or an attribute of His, based on the saying of the Prophet, peace and blessings be upon him: "Whoever swears by other than Allah has committed shirk (polytheism)." This applies to both Muslims and disbelievers, as disbelievers are bound by the subsidiary rulings of Sharia. It is not permissible to ask them to swear by other than Allah. Scholars have stated that if an oath is required from a disbeliever, they must only swear by Allah, even an atheist who does not believe in the existence of Allah must swear by Allah.

If a Muslim asks a non-Muslim to swear by their god, and does not intend thereby to glorify that god, they have committed something forbidden. However, it does not constitute major disbelief, because swearing by other than Allah is minor disbelief. It could become major disbelief if one intends to glorify the object of the oath in a manner similar to or greater than the glorification of Allah. A Muslim who does this is either ignorant or misinterpreting, and after knowing the Sharia ruling, they must refrain from doing so.