I wonder what Peter was thinking.
Seriously, what kind of a thing was that to say to a being that you see walking towards you on the surface of the water, in the middle of a stiff wind? The other disciples are already freaked out, having come to the logical conclusion that the only thing that could do something like that is a ghost.
Sure, this being says it's Jesus, but that's what you'd expect a tricky ghost to say, wouldn't it? If it's a ghost, you can't trust it. So Peter says, "If it's you, Lord, tell me to come to you!" What did he expect to hear? If he believed it was Jesus, did he expect him to say, "C'mon, Pete! Just because I do it doesn't mean you can! Just wait a minute and I'll be right there." Because if it's a spooky ghost, it might just very well say, "Come," and then stand there laughing while he sank like the rock he was named for.
Anyway, he says what he says, and Jesus says, "Come," and Peter gets out of the boat and starts walking. But as soon as he starts to notice his surroundings he gets scared and starts sinking. So he calls out -- notice all traces of uncertainty are gone -- "Lord, save me!"
There seem to be two different reasons given for Peter's sudden lack of buoyancy. Matthew says he "became frightened," and Jesus' words suggest he doubted and lost faith. I think they're two sides of the same coin, cooperating to produce this disappointing result. And they stem from the same root: Peter takes his eyes off of Jesus and begins to pay more attention to what's around him than he does to what he's headed towards.
On a simple level, that seems obvious: Take your eyes off of Jesus and you've got trouble. But that's the kind of idea that can unfold into something larger. Although Jesus would later give Peter the much larger charge of leading the entire church, here he gives the simplest of directions: "Come." Whatever larger call God may also have on our lives, it wraps around the simplest one, which is to follow him.
Organizations and even people have over the last several years become fans of buzzword-heavy planning sessions to develop "mission statements," "strategic plans" and "tactical objectives." The ideas are simple and important: Figure out why you're here, what you want to do and how you're going to do it. I sometimes think the people who use all the other phrases didn't get to play Army enough when they were kids.
However that may be, churches and Christians ourselves have mission statements as well, because we also need to know and say why we're here, what we want to do and how we're going to do it. My own denomination in 2004 said its mission was "to make disciples of Jesus Christ." In 2008 we tweaked it, adding "for the transformation of the world," apparently to distinguish us from those who were making disciples that didn't transform the world.
Ideally, a mission statement not only keeps you from doing things that don't help it, it also shapes the things you are doing, perhaps giving them a new purpose and energy along with a new direction. When we turn aside from the mission, we can find ourselves in a rising tide of busy-ness and distraction, not nearly as capable of focusing on that primary goal.
Life will throw things at us, not because it's got any active interest in our failure but because that's just what life does. And some of those things will distract us from Jesus' simplest call to follow him, because we're flawed human beings who mess up. Fortunately, when that happens and we find ourselves sinking into the mess we've wound up in, we need only call on the one we should have been paying attention to all along, and we find him swift to save.
Because he never forgets his mission, and his mission is saving the creation of his Father -- you and me.