envy vs mortal sin

envy and mortal sin both are nouns.

Word	Noun	Adjective	Verb	Adverb
envy	Yes	No	Yes	No
mortal sin	Yes	No	No	No

As nouns, mortal sin is a hypernym of envy; that is, mortal sin is a word with a broader meaning than envy:

envy: spite and resentment at seeing the success of another (personified as one of the deadly sins)
mortal sin: an unpardonable sin entailing a total loss of grace

Other hypernyms of envy include deadly sin.

envy (noun)	mortal sin (noun)
spite and resentment at seeing the success of another (personified as one of the deadly sins)	an unpardonable sin entailing a total loss of grace
a feeling of grudging admiration and desire to have something that is possessed by another

envy (verb)	mortal sin (verb)
be envious of; set one's heart on
feel envious towards; admire enviously