Saint Luke vs Luke

Saint Luke and Luke both are nouns.

Word	Noun	Adjective	Verb	Adverb
Saint Luke	Yes	No	No	No
Luke	Yes	No	No	No

As nouns, Saint Luke and Luke are synonyms defined as:

Saint Luke and Luke: (New Testament) the Apostle closely associated with St. Paul and traditionally assumed to be the author of the third Gospel

Other synonyms of Saint Luke include Luke the Evangelist, St. Luke.

Saint Luke (noun)	Luke (noun)
(New Testament) the Apostle closely associated with St. Paul and traditionally assumed to be the author of the third Gospel	one of the four Gospels in the New Testament; contains details of Jesus's birth and early life
	(New Testament) the Apostle closely associated with St. Paul and traditionally assumed to be the author of the third Gospel