User blog comment:Xilinoc/Ch. 570 (I can't think of a witty title at 11 pm)/@comment-29183117-20140226133717/@comment-8669536-20140226151110

I Think all Echt had at least some knowledge of Quincy tradition, otherwise it strikes me as odd that they managed to retain their purity. Seems a strange coincidende that they would just happen to marry and have children with other Echt Quincy for two hundred years.

Maybe the Echt families had knowledge of the Quincy tradition, just the knowledge was not really accurate. They were aware of the "good´" Quincy and believed them to be on the side of God, while they thought their Clans had been wiped out by the "evil" Shinigami. They had kind of adapted their tradition into their own version of Christianity.

Äs seems to have lived in the west judging from the western writing on the book (it seems to say "ibel", and I assume the full text is "Bibel", which is the Swedish/German word for "Bible".) while the Ishidas lived in Japan, thus the Ishidas were unaware of all non-Japanese remaining Quincy probably. But other Echt existed in other parts of the World.