The word celestial is primarily used to describe things that have to do with the heavens such as angels, spirits, stars and planets. It does not come from words meaning God or soul though, but from the Latin word for sky caelestis, which also gave rise to the word ceiling. So really, all you have to do is look up and you'll remember what celestial means — whether you're inside or outside.
Wallis's New Game of Wanderers in the Wilderness. Hand-coloured etching on linen, published 1818-1847. The Wilderness in this case is South America, a country continent that would have been unknown and mysterious to most people at the time that this game was published.