good spirit vs guardian angel

good spirit and guardian angel both are nouns.

Word	Noun	Adjective	Verb	Adverb
good spirit	Yes	No	No	No
guardian angel	Yes	No	No	No

As nouns, guardian angel is a hypernym of good spirit; that is, guardian angel is a word with a broader meaning than good spirit:

good spirit: a benevolent spirit
guardian angel: an angel believed to have special affection for a particular individual

Other hypernyms of good spirit include guardian spirit.

good spirit (noun)	guardian angel (noun)
a benevolent spirit	an angel believed to have special affection for a particular individual