hi doma,
i think your post contained a cross (the christian cross noticeably does not employ a cubic measurement structure), a cube and a square.
these are what we call shapes!!;-)
there are only so many regular shapes. because of this of course they are used repeatedly. the fact they are used repeatedly is not evidence of a historical relationship.
not that numbers weren't used in religion. but to tie them together merely because they involve squares isn't sufficient in my view.