The story of Jesus walking on water immediately follows the story of Jesus feeding 5,000 men (plus women and children) in the gospel of Matthew. Matthew chapter 14 begins with Herod beheading John the Baptist to satisfy a pretty girl. After Jesus learns of John's execution, he goes off by himself. But soon enough, the crowd finds him, and he "had compassion on them and healed their sick."
I love the picture of Jesus' character (and the challenge it presents for us as his followers) in these few lines. Jesus is heartbroken. John had baptized Jesus, after all. They were cousins. And Jesus was mourning. But when the crowds found him, crowds that were also hurting, Jesus had compassion on them and healed them. I'm so thankful that Jesus has compassion on me even as his heart breaks. I pray for that kind of compassion!
Now that the crowds have surrounded Jesus, they need to eat. So he tells the disciples to feed the crowd. The disciples protest, "We have only five loaves here, and two fish." Jesus asks for what they have though, and the 5,000 men (plus all of the women and children that were there) were fed, with 12 baskets of leftovers!
Jesus then sends the disciples out onto the sea, but Jesus stays on land to dismiss the crowds. The bible says this happens "immediately" after the leftovers were collected. So we're not talking about a long period of time passing between the feeding of the 5,000 and the walking on water. But as Jesus approaches the boat on foot, the disciples are terrified. Jesus identifies himself, but the disciples don't believe him. They've just watched him use five loaves of bread and two fish to feed more than 5,000 people, but they don't think he can walk on the sea.
So Peter essentially challenges him. "If it's really you, command me to come to you." Now, I have to be honest, I feel like this was a dumb challenge for Peter to issue! "Hey, if it's you, tell me to do something dangerous that might kill me!" But, that's what Peter says, and Jesus tells him to "Come."
Peter walks on the water, but before he reaches Jesus, he has a chance to process exactly what he's doing. He sees the wind, gets scared, loses his faith, and starts to sink. And that's when he cries out, "Lord save me!" How often have you answered God's call, only to look around, realize how crazy following God can be, and started to sink? But even in Peter's doubt, Jesus saves him. Even in my doubt, Jesus saves me.