I know it's a stretch and way beyond my knowledge, but Light, no time passing, but time passing for other observers.. struck me as ponderable - for a dilettante anyway.
In that view, the spiritual realm "there" is actually the physical realm "here" - not spatially separated.
That the firmament is a boundary, but not a geometric one rings true in my spirit. But I have no Spiritual leaning - for or against - that boundary being the speed of light.