At 4, I convinced my dad I was ready to cycle the big-boy bike. I sat on the cross-bar and peddled while he held the saddle and ran next to me. Faster and faster we went. This was a piece of cake, until I realised that he was no longer holding the bike and was way, way behind me. Only problem was the T-Junction ahead and I had not learnt about brakes.

See Matthew 14:22-33 (http://bit.ly/2pPqrv5)

What is important is not that Peter sank, but that even with a little faith, he was the only Disciple to walk on water. The others only watched.