Hitler only tolerated reading of the New Testament and railed against the Old Testament. He personally worshipped Norse gods.
Suggest your take some time and read Hitler's "Table Talk". He clearly viewed Christianity and Judism in the same light and had for each the same goal.
I am sure that had he made his thoughts public, his universal appeal would certaily have suffered. Use of the religious symbols by the Nazis was a convenient ruse similar to Stalin's sudden "return to religion" after being attacked by Germany.
The Nazis used any religion to further their power. For example, the Nazis raised two Muslim Waffen SS Divisions during the war. These were the only true "religious" SS Division the Nazis ever created (and it is safe to say that the Germany was not a Muslim nation). Himmler was fascinated by the thought of Muslims to be fearless soldiers willing to kill for their religion. One of these Muslim Waffen SS divisions (The Hanjer Division) was responsible for the murder of over 90 percent of the Yugoslavian Jewish population. And these Muslim Waffen SS Divisions did where Islamic religious symbols on their German Army uniforms...