John 6:16-20

And when even was now come, his disciples went down unto the sea, and entered into a ship, and went over the sea toward Capernaum. And it was now dark, and Jesus was not come to them. And the sea arose by reason of a great wind that blew. So when they had rowed about five and twenty or thirty furlongs, they see Jesus walking on the sea, and drawing nigh unto the ship: and they were afraid. But he saith unto them, It is I; be not afraid.