User blog comment:B214/Question and Answers 6/@comment-185.112.105.215-20161019113453/@comment-29963364-20161019204636

Actually, Holy Power and Light are two different things.

There's "Holy Power", then there's "Holy Light."

The Angels have "Holy Power" and they have the ability to create and manipulate "Holy Light."

What makes an Angels power and/or light "Holy" is the "Heaven System" that was created by the Biblical God. The "Heaven System" is like a world-wide enchantment spell network (enchantments are spells that are "cast onto" an object or person which buffs or debuffs them).

Holy Power, Holy Water, Holy Swords, and Crosses are all under the effects of the "Heaven System" and are therefore "buffed" with the "Holy" quality.

The "Holy" quality of course has an obvious effect: "Holy" objects have increased offensive/defensive capabilities against Devils/Demons.