There was good reason that the Jews were strong supporters of the German Empire... the Kaiser's Germany was comparatively one of the more egalitarian regimes in Europe in their treatment of their indigenous Jewish minority. I'm not saying it was Meshuval Wine and Roses for the German Jews; just that the Kaiser's regime was *comparatively* friendly towards the Jews. (I'll defer to Goetz_von_Berlichingen for any specifics he'd care to offer).
By comparison, Hitler's anti-Semitic program was, as RobbyS points out, racialist -- not religionist -- in it's "operational theory"; and Racialism is (predominantly) a secular phenomenom. (As far as personal "Devotions" go, you'll find more Alcoholism and Pederasty amongst the Nazi elites than you will Rosaries).
A number of embittered German in the Post-Versailles period were looking for a scapegoat, and the Jews happened to be the target of choice for a certain demonically-charismatic demagogue. It could've equally well been any other Racial Minority, say the Gypsies for example (actually, it was them, also).
If "religion" were the motivating force, one would have expected the Nazi anti-semitic Laws to offer various exemptions for confessing "Christian" or "Messianic" Jews. I don't recall there being any.