How to pronounce “christian religion” in English

It may be that there were ancient authors who thought that their views of this Christian religion were so spot on and so important and really needed to be widely accepted, that

And his devotion to checkers was-- seemed to be just as strong as his devotion to his Christian religion.

For people who are religious, it's been the basis of the Christian religion for two thousand years.

Why is it that we have the Trinity, which absolutely makes no sense to anyone outside the Christian religion?