Only a child would say to someone walking on water during a storm in the middle of the night, “that is so cool, can I come too?” That is effectively what Peter says. Jesus did not say, “O Peter, walking on water is for big boys, you are not there yet.” He put no barrier whatsoever before Peter. He simply said, “Come.”
Peter steps out of the boat, doing what he saw Jesus doing. Walking on water calls for resources beyond human. It takes you far beyond human limitations and the slightest deviation from reality will cause you to sink. Peter started to sink when he became afraid, but he called on Jesus to save him and of course, Jesus instantly did. Peter did not sink. He walked on water just like Jesus, even though He doubted!
Life is most exciting when we venture to walk on water.
The only reason the impossible eludes most of us is because we are too serious, too reasonable. You can walk on water too if only you would allow yourself to be be a child.
When He said “all things are possible to whoever believes,” Jesus is effectively saying “Come”, like He said to Peter. Even if you momentarily start to sink due to your own fault, the Master will catch you immediately you call on Him. What a no-brainer! The other disciples only needed to say, “me too” and Jesus would have said, “come” but they were too serious to entertain the thought.
The world is in dire need of people childish and unreasonable enough to walk on water. Your only regret at the end of the day will be remaining in the safety of the boat. Really, what do we have to lose?