St. John the Apostle vs Saint John the Apostle

St. John the Apostle and Saint John the Apostle both are nouns.

Word	Noun	Adjective	Verb	Adverb
St. John the Apostle	Yes	No	No	No
Saint John the Apostle	Yes	No	No	No

As nouns, St. John the Apostle and Saint John the Apostle are synonyms defined as:

St. John the Apostle and Saint John the Apostle: (New Testament) disciple of Jesus; traditionally said to be the author of the 4th Gospel and three epistles and the book of Revelation

Other synonyms of St. John the Apostle include John, John the Divine, John the Evangelist, Saint John, St. John.

St. John the Apostle (noun)	Saint John the Apostle (noun)
(New Testament) disciple of Jesus; traditionally said to be the author of the 4th Gospel and three epistles and the book of Revelation	(New Testament) disciple of Jesus; traditionally said to be the author of the 4th Gospel and three epistles and the book of Revelation