Praise be to Allah.
Ruling on enrolling in Christian schools
In the answer to question no. 13302 , we explained that there is nothing wrong with enrolling in Christian institutions, if the aim is to acquire beneficial worldly knowledge, and there is no fear that the faith, creed (‘aqeedah) and morals of the student will be corrupted.
But undoubtedly avoiding them is more prudent for the Muslim, for so long as a person is alive, he cannot be sure that he will be safe from fitnah (temptation or confusion). So what Muslim should always do is err on the side of caution, and not take risks with regard to his faith and creed, for there is nothing like being safe.
All of this applies if the school or college offers no courses that teach disbelief and evildoing, and does not oblige students to show respect to symbols of disbelief or accept them.
But if the school forces students to study the Bible, or to visit churches and listen to their prayers and sermons, or in their curriculum they teach their false religions or the curriculum contains evils such as teaching students how to dance, play musical instruments and the like, then it is not permissible to study in these institutions.
Ruling on clothing if crosses and symbols of disbelief are removed from it
If the crosses and symbols of disbelief are removed from the clothes, and they no longer have the same look that makes them resemble the type of clothing that is unique to disbelievers or those who follow their religion or their monks, then there is nothing wrong with wearing them.
See the answer to question no. 5227 .
We have previously explained the ruling on addressing a Christian priest as father, which is either done out of respect and veneration for the priest, as the Christians themselves do, which is undoubtedly not allowed, because it is imitating them, and that is not permissible;
Or it is done to identify him and speak of him, because this is a title that he has been given and is known by, and it is not done with the intention of imitating the Christians or showing respect and veneration to the priest. Identifying people is a flexible matter, hence it is permissible to identify a person in terms that in principle are regarded as backbiting, if that serves the purpose of identification.
And Allah knows best.