Saint Luke vs St. Luke

Saint Luke and St. Luke both are nouns.

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

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

Saint Luke and St. 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, Luke the Evangelist.

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