Yes, I believe Peter did fail. When doubt happens, you fail. Though it is hard to say if anybody did really walk on water, this is where my beliefs come into play "Ye of little faith." I am of little faith.
             You are climbing a rock face with your friend "Jimmy," the supposed expert. Jimmy is higher up and has reached a ledge where the two of you plan to take a little break before you continue your journey. He is safely secured to the ledge and you are safely tethered to him. So, you're a bit behind, hanging on the rock face, trying to decide how you got talked into this. You reach up for a hand hold, loose rock, so you try another; this one feels a bit more secure. As you pull your weight, the rock gives loose. "Rock Down!" you yell.
             "Are you ok?" Jimmy asks, as he looks down while coiling his ropes for the assent.
             "Yeah, just a bit shaken," you reply. Now you look for another place to grab onto, to get to your bittersweet reward -the break. Another bad choice, "Rock Down!" you yell again.
             "Are you ever going to get up here?" Jimmy asks jokingly.
             While ignoring his comment you reach for another hand hold, again it is a bad choice, another rock down. This breaks your confidence, and you can't stop the thought of how you're going to die, right here on this rock face while he makes it look so easy.
             "I can't do it!" you beckon to him.
             "Yes, you can!" he commands. There's a hold right there, just to the right." Jimmy pauses, waiting for you to see the hand hold.
             "Where your hand was just at!" he snaps sternly enough for you to realize he's serious now.
             "No, it'll give way," you whimper in reply, "like the others did."
             "Ye of little faith, that's the one I used. Now get up here and have some water!"
             ...