I don't think Jesus' disciples were afraid of the water that day, or even the wind that was so contrary. I believe the fear came when they were unable to recognize the object moving towards them (because it's the unfamiliar that moves towards you in the familiar that brings the fear.) They knew the water, but this was a storm like no other, and they didn't have "sleeping Jesus" in their boat this time. They were completely alone. Jesus wasn't in this storm, or so they thought.
But when the unfamiliar moved towards them, He confirmed that it was Him... it was Jesus. Peter still wasn't sure, so he said,"If it is You,...", because when the storm comes, a vision of Jesus is often clouded.
I love what Peter asks of Jesus next: "Command me to come to You, Jesus". He doesn't ask Jesus to meet him halfway for the rescue. He doesn't ask Him to move at all. No, Peter is the one that wants to move. Peter is the one who wants to walk on water, just like Jesus. In the New Living Sagely translation I read Peter's heart like this: "I want to come to You, Jesus. I want to be where You are. I want Your authority over this element I've depended on all of my life; the one I thought I could control. I know now that I can't. I also know that I need to be able to walk on this water just like You, Jesus. I want to be with You. I want to follow You on that dry land, where the world is waiting to hear Your message of grace and truth. I want to tell them, just like You've commanded me to do. But I can't sit in this boat right now, and sail back to that shore until I've walked into the doubt and fear that's right here; until I've conquered it. My faith is small, but You are bigger, and I need a bigger faith, Jesus. I want to worship You; I really do. But You have to prove to me that it is You in this storm; that the voice I hear is Yours. That You are the Certainly that all my friends in this boat will soon call You. So stop the wind, Jesus, and take away the fear. And be my Certainly in this storm".
"And Peter got out of the boat, and walked on the water, and came toward Jesus" (Matthew 14:29)
