He [Jesus] 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.” (Matthew 14:29-33)
There is a difference between belief and faith that produces action. As has been well said, Faith is belief with legs on it.
I can’t help but wonder, what was the sea like for Peter? Was it slippery? Was it like concrete, or was it like Jell-O? I don’t know. But here’s fisherman Peter out there; he’s made his living on that water. So, trusting in the word of the Lord to “come,” Peter steps over the side of that boat, puts his feet down on something solid, and begins to walk. He says, “This is wonderful, look at this! I’m walking on the water.” Then, about that time, he sees some wave, maybe it slaps him in the face. He looks around and he stops saying, “This is wonderful.” He now says, “This is impossible, I can’t do this!” And he begins to panic. Peter takes his eyes off Jesus and puts them back on the storm. And when he does, he begins to sink.
Before we think too harshly about Peter for taking his eyes off Jesus, just remember that there were 11 other guys back in the boat watching this whole thing. As long as you stay in the boat, you’ll never sink — but you’ll never walk on water, either. Faith is investing everything in God’s faithfulness. It is committing yourself to the Word amidst the waves.