Is it permissible for a Muslim woman to eat, drink, and jest with a young Christian man whom she is helping to study Islam, or not?

It is permissible to interact with a Christian young man in ways that do not contradict Islamic creed, such as showing kindness and benevolence towards him and not oppressing him, based on the Almighty's saying: "Allah does not forbid you from those who do not fight you because of religion and do not expel you from your homes - from being righteous toward them and acting justly toward them. Indeed, Allah loves those who act justly." It is also permissible to eat and drink with him as long as the food and drink are Islamically permissible, because the impurity of polytheists is spiritual, not physical.