Immediately he made the disciples get into the boat and go before him to the other side, while he dismissed the crowds. And after he had dismissed the crowds, he went up on the mountain by himself to pray. When evening came, he was there alone, but the boat by this time was a long way from the land, beaten by the waves, for the wind was against them. And in the fourth watch of the night he came to them, walking on the sea. But when the disciples saw him walking on the sea, they were terrified, and said, “It is a ghost!” and they cried out in fear. But immediately Jesus spoke to them, saying, “Take heart; it is I. Do not be afraid.”

And Peter answered him, “Lord, if it is you, command me to come to you on the water.” He said, “Come.” So Peter got out of the boat and walked on the water and came to Jesus. But when he saw the wind, he was afraid, and beginning to sink he cried out, “Lord, save me.” Jesus immediately reached out his hand and took hold of him, saying to him, “O you of little faith, why did you doubt?” And when they got into the boat, the wind ceased. And those in the boat worshiped him, saying, “Truly you are the Son of God.” (ESV)