Considering that the Old Testament explicitly defines the jewish people as "the chosen", and that it is an integral part of the Bible according to many christian denominations, and that Christ was born jewish, how did they regard the scriptures?
Christianity and Nazism is a fascinating topic. I would suggest seeking out the work of Doris Bergen (Twisted Cross: The German Christian Movement in the Third Reich), Robert P. Eriksen (Theologians Under Hitler) and Susannah Heschel (The Aryan Jesus: Christian Theologians and the Bible in Nazi Germany). They can explain it much better than I can, however I will attempt to distill it.
Essentially, Christian theologians (mostly Protestants, but some Catholics as well) "Aryanized" Jesus. They essentially argued that because Jesus attacked the Jewish establishment through his teachings, his literal attack on the money-changers at the Temple, and his followers' subsequent abandonment of the Old Testament, that Jesus himself was not Jewish. They also argued that Jesus was an ethnic Aryan, not an Israelite or anyone related to the contemporary residents of the Middle East. Therefore, there was no conflict in their minds between Christianity and Nazi antisemitism. It may seem ridiculous to us, but serious, respected, highly qualified German theologians made these arguments in all seriousness.