Although I'm not Catholic, I will give confession - I have absolutely NO idea of why there is discussion of religion on this site. It has nothing to do with martial arts. I know of nothing in anybody's bible that gives significant instruction or insight into personal combat. And I know of nothing in martial arts that depends upon any particular religious belief. Christians, Atheists, Deists, Buddhists, Muslims, Jews, and lessor known religious followers all do martial arts pretty much the same. There is no Jewish front kick, no Christian arm bar, no Buddhist left hook, etc.
There are some Oriental philosophical concepts such as hard / soft balance, empty mind, and others that can directly affect the performance of martial arts physically, mentally, or aid in perception and reaction time. One may point out religion offers general moral guidance, but knowing it's wrong to hurt innocent people or otherwise misuse the art does not require religion.
I would not limit my students to those of any particular religion, just as I would not restrict those that are vegans, democrats, plumbers, cat lovers, men, college grads, etc., since none of these things affect them doing martial arts. (Some of these people I may think strange, but I would teach them all the best I can) All I need in my class are good hearted people willing to do their best and respect others. Any religion that advocates these ideals are welcome.