Zen is consciousness unstructured by particular form or particular system, a trans-cultural, trans-religious, trans-formed consciousness.

It is therefore in a sense "void".

But it can shine through this or that system,  religious or irreligious,  just as light can shine through glass that is blue, or green, or red, or yellow.

If  Zen has any preference it is for glass that is plain, has no color, and is "just glass."