"Matthew, Mark, Luke, and John,
Bless the bed I sleep upon,
Four corners to my bed,
Four Angels round my head,
One to read, and one to write,
And two to guard me all the night."

Probably this was originally an allusion to the four cherubim who are the emblems of the Gospels.  It is remarkable that these four Evangelists should in their very names show the languages most intimately connected with the out-spread of the Gospel, two being Hebrew, one Græcised Latin, and one pure Latin. (History of Christian Names, Yonge, 1884)

JOHN.  [Gr. Ioannes, from Heb. Yohanan (Johanan)]
    (1) John the Baptist.  The immediate forerunner of Jesus, whose way he was sent to prepare.  He was born in B.C. 3 (?), about six months before the advent of Jesus.  His birth was promised by an angel to Zacharias when the latter was burning incense in the Temple at Jerusalem, and the Divine will was expressed that the child when he came should be called John (Luke i. 5-13).
     (2) The father of the Apostle Peter (John i. 42—R.V.; xxi. 15-17—R.V.).  [Jonah (2).]
     (3) John the Apostle.  The younger son of Zebedee, and brother of that James who suffered martyrdom under Herod Agrippa I.  His mother's name was Salome (cf. Matt. xxvii. 56 with Mark xv. 40).  His father was a master fisherman on the Lake of Galilee, his two sons aiding him in his occupation (Matt. iv. 2; Mark i. 20).  While James and John were so engaged they were called by Jesus to be apostles (Matt. iv. 21, 22; x. 2; Mark i. 19, 20; Luke v. 10, 11).
     (4) John Mark.  Mark the evangelist.  Mark, however, was only the surname; John was the proper, and probably the earlier name. [Mark]  (Cf. Acts xii. 12, 25; xiii. 5, 13.)
     (5) A Jewish dignitary who took part with Annas, Caiaphas, Alexander, and "as many as were of the kindred of the high priest," which perhaps he was himself, in calling the apostles Peter and John to account for their preaching (Acts iv. 6). (Sunday School Teacher's Bible Manual, Hunter, 1894)