What is the meaning of the last line of the series?

The very last scene shows Kai surfing and John's voice over is "Mother of God, Cass Kai" or as I interpret it "Cass-Kai." I think the reference is to Mary the mother of Jesus and the composite of two women who loved and cared for him during his time among them. When I heard the line it sent shivers down my spine. - User:Edward212
Category:Theories