Well, I've never seen someone play it at a big competition. They play Busoni, they play Kempff, but they just don't play this piece! So, I was wondering if devout Christians would find it akward, or even immoral, if I played this piece at a competition.
i have never heard of kempff being played at a major competition, unless you're referring to the kempff transcriptions. This is of course assuming that we are referring to the same definition of major competition, e.g. Van Cliburn, Leeds, Cleveland, Honens ...etc.
Liszt's religous works, while very spiritual, are not sacred works per se, but rather personal musical expressions of his religious sentiments. The same could be said about Messiaen's Vingt Regards. As a competition piece, the benediction has a tendency to incite disagreement in the jury as to how to best interpret the music, due to the personal nature. However, this is a masterwork of Liszt's piano output and can fit into any major competition program, when programmed and performed with intelligence and taste.