It may be contradictory for Brendan to believe in one and not the other, but in truth it is quite normal of the Irish people. If you have ever been to Ireland, and this statement might be hard to digest if you have not, but the landscape itself lends one’s imagination to the notion of faerie and other magical beings. There a huge rolling hills full of common and private land that can disappear instantly in a low cloud. It is easy to believe in faerie just by looking out your back window at the fog that devours something so huge and stops so abruptly at your front door. Whereas for Crom Cruach, I believe that the evil is not found in the environment but inside of the people. Not saying that the Irish people are evil, they are all very wonderful and colorful with an abundant supply of love and neighbor-friendship, but they have demons inside of them that they must conquer much like Brendan conquers (very courageously) Crom Cruach. I think the fact that Brendan so easily and whole-heartedly believes in faeries and not Crom Cruach is a perfect representation of the Irish beliefs then and now.