Reverential capitalization
Reverential capitalization is the practice of capitalizing religious words that refer to deities or divine beings in cases where the words would not otherwise have been capitalized. Pronouns are also particularly included in reverential capitalization: and God calleth to the light 'Day,' and to the darkness He hath called 'Night;' and there is an evening, and there is a morning — day one.
Source: Wikipedia — Reverential capitalization (CC BY-SA 4.0)