living vs life eternal

living and life eternal both are nouns.

Word	Noun	Adjective	Verb	Adverb
living	Yes	Yes	No	No
life eternal	Yes	No	No	No

As nouns, life eternal is a hyponym of living; that is, life eternal is a word with a more specific, narrower meaning than living:

Other hyponyms of living include eternal life, skin, endurance, survival.

living (noun)	life eternal (noun)
the experience of being alive; the course of human events and activities	life without beginning or end
people who are still living
the financial means whereby one lives
the condition of living or the state of being alive

living (adjective)	life eternal (adjective)
pertaining to living persons
(informal) absolute
still in existence
(used of minerals or stone) in its natural state and place; not mined or quarried
true to life; lifelike
still in active use