John is a Hebraic name derived from the phrase "God is Gracious". It comes from the Yahwist tradition in which the name of God is ("Yahweh"). Its original form is ("Yahuhanan"). We can see John's two constituent words, ("Yahweh" = God) and ("Hanan" = Gracious), at work in verse 8 of David's 103rd Psalm...
(The Lord is merciful and gracious, slow to anger, and plenteous in mercy.)
Other names derived from the Yahwist tradition are Joshua, Jonathan
There are also many Hebraic names which have derived from the Elohist tradition. In the older Elohist tradition, the name of God is ("Elohim"). Examples of such names are Michael, Daniel and Elizabeth.