LOL. That was the equivalent of the WMD excuse of our day.
I believe the real reason--from the Church's standpoint--may have had more to do with politics:
Rome figured if it controlled the Holy Land, then other Christian religions would appear false, and thereby Roman Catholicism would have a monopoly on Christianity.
And there was no shortage of nobles who saw the Crusades as a chance to add mid-eastern fiefdoms to their domains.