These were individuals who broke away from Christianity but who still believed in God. They just did not belong to any formal religious organization, just like 85% of Americans today.
The Nazis did not approve of religious organizations, but they didn’t require atheism of party officials either, like the Soviets, the modern Chinese; nor did they physically destroy any Christian churches.
The popular conception is that the Nazis hated Christians as much as they hated Jews. Their only physical act was to remove the Old Testament from the Bible, but even that was mostly symbolic.
The Nazis simply believed that Christianity was not healthy for or compatible with the German psyche. That was nothing new.
The Protestant Revolution was centered in Germany, perpetuated by Martin Luther et al.
Atheism
Atheism was actually synonymous with Marxism and the Soviet Union. Thus, in every sense of the word, atheists were the Nazi’s archenemy.
Here in America, atheists have the run of the land. They regularly sue to have Christian war memorials removed from public areas, Christmas decorations taken off public property, Ten Commandment displays removed from U.S. courthouses, Bibles from inauguration ceremonies, God from the dollar bill, and God from the vocabulary of all public officials and public employees (teachers, coaches, school officials, politicians).
Such vile actions would never have been permitted by the Nazis because they’re the work of the devil – aka Marxists.
Nature Worship
Nazis were hip on what we call Wicca now, respect of nature in a spiritual way. They revered their Celtic roots and developed ceremonies to bring people closer to Mother Nature and their farming roots.
The Nazis reveled in the mysteries of the occult, the science- beyond, the unknown and the unknowable. All the things that formal religions say are evil: natural healing, meditation, visualization, inner focus.