Mark 4:41

And they feared exceedingly, and said one to another, Who then is this, that even the wind and the sea obey him?

Mark's purpose in his gospel shines in such an expression as this, of which there are a number of examples. He intended that the mighty works of Christ should lead to they identification of Jesus Christ as a supernatural person, one with the Father, and fully able to give eternal life to them that come unto God through him.