The last PPPS reminds me of the joke:
In 1905, in Listowel, a folklorist asked an elderly lady if she believed in “the Good People” (fairies & leprechauns).
“Well, no I don’t. But it doesn’t seem to matter, they’re there just the same.”
This is a joke, but it shows that although the lady doesn’t believe or love the idea of the Good People existing, yet still she is persuaded they do.
I am not familiar with the course of the many adjacent rivulets of meanings of “glauben” in German since Proto-Germanic, but it would not surprise me if the influence of translating “episteuo“ into ”glauben” had a similar effect on those rivulets of meaning as they have had in English.
By the way, German scholarship in Koine Greek was rudimentary in the early 1520s when Luther and his team were translating the Bible into a compromise dialect of German (indeed, Luther’s Bible had the effect of greatly influencing and standardizing what became modern German).