Stay in the boat!
I've heard quite a few sermons on this text that basically come down to a commendation of Peter's faith for getting out of the boat and walking on the water. The problem, as it is usually put, is that he takes his eye off Jesus, and his faith falters, but Jesus is there to save him. So, the sermon concludes, be courageous, get out of the boat, but keep your focus on Jesus.
Okay, that may be good encouragement for some people to put their faith into action, but it kind of misses the point of the story. After all, when they get back in the boat, the other disciples don't congratulate Peter for doing pretty well and wish him better luck next time! The real hero in the story is Jesus whom the disciples worship (for the first time in Matthew) as the Son of God.
Matthew 14:22-33 needs to be read in parallel with the Stilling of the Storm account in 8:23-27, but we want to keep the two stories straight. In the first story, there is a great storm, waves swamp the boat, and the disciples fear for their lives while Jesus sleeps. Waking him up with the plea, "Lord, save us!" Jesus calls them cowardly "ones of little faith," rebukes the winds and sea, and brings about the calm. In response, the disciples are amazed and can only wonder what sort of person Jesus is that "even the winds and sea obey him."
In contrast, in the 14:22-33 lesson, there is again wind and waves, but no storm, and the disciples are not fearing for their lives. What does cause them to be afraid is seeing someone walking on the water and thinking it's a ghost. Jesus reassures them without scolding as before, and then Peter poses his challenge to Jesus. He starts to sink because he "sees the wind," becomes afraid, and cries out "Lord, save me!" (Note the similar wording to the previous time.) Jesus grabs hold of him, and this time only Peter is called "one of little faith" and questioned for doubting. The wind simply ceases once Jesus gets into the boat, and this time the disciples worship him as the Son of God.
In terms of Matthew's narrative intent, we want to see what has developed between the two stories. The disciples' fear is more reasonable the second time: Jesus is not with them, and the phantasm they see is beyond anything they have experienced. The main difference, of course, is Peter's request for Jesus to identify himself by allowing him to walk on the water. I don't think we are to commend him.
Jesus has clearly identified himself by telling the disciples to "Take heart," something he also says in 9:2 and 22, and the people do so. He declares, "I am," with its divine overtones. He says, "Don't be afraid," which he regularly declares in Matthew. (10:26, 28, 31; 17:7; 28:10) So when Peter says, "If it is you..." (ei su ei in the Greek), then he is joining the company of Satan (4:3, 6), the high priest (26:63), and the mockers at the cross (27:40) who all put the same challenge to Jesus. In each case, just like Peter, they want Jesus to do something in order to verify his identity. This is not a good thing...
Unlike the other times, however, Jesus does grant the request to Peter, but there should be no surprise that matters are not going to end well for him. So, is Matthew intending the reader to realize that no disciple is totally worthless, because he can always serve as a bad example? Not quite. First, it's an enactment of the truth that we are not intended to walk on water, and if we try, we will find ourselves in deep over our heads and unable to save ourselves. Second, Peter does rightly know what we all need to do when caught in situations like this and sinking like a rock: "Lord, save me!"
In both accounts, Jesus demonstrates that he is Lord of the wind, waves, water, and sea, all of which are characteristic of chaotic elements in nature. Quite appropriately then, we also notice that at the end of the second account, instead of just wondering what sort of person Jesus is, the disciples worship him as Son of God. The next time Matthew records that the disciples worship Jesus is when he fantastically appears after his resurrection (28:17). It seems, then, that Peter's question is not whether one who walks on the sea is the Son of God but whether that person is Jesus. This incident does not necessarily 'prove' that Jesus is the Son of God. After all, the disciples first thought it was a ghost, and Peter himself momentarily accomplished the feat. When you start adding all the pieces together, however, it is a part of the picture that confirms Jesus' identity. It also confirms that Peter is not the Son of God!
We also should note that in both the account in 8:23-27 and our text at hand, Jesus ends up in the boat with the disciples. A ship was one of the earliest symbols for Christianity, and this story indicates why it was attractive: when surrounded by adversity, safety and salvation are experienced in the church with Jesus in its midst. But remember that a ship is not a static symbol. It is a vehicle used to get somewhere. Ultimately, we may ask, "Why did Jesus and the disciples cross the sea?" The answer is given in 14:34-36. They wanted to get to the other side to minister to those people there. So, leave walking on water to Jesus. That ship which is the church is where we want to be, and it can provide the way for us to get to other places, so that disciples of the Son of God can be moving throughout the land!