And when evening came, the boat was out on the sea, and he was alone on the land. And he saw that they were making headway painfully, for the wind was against them. And about the fourth watch of the night he came to them, walking on the sea. He meant to pass by them, but when they saw him walking on the sea they thought it was a ghost, and cried out; for they all saw him, and were terrified. But immediately he spoke to them and said, “Take heart, it is I; have no fear.”
–Mark 6:47-50