Walking on water is an iconic, superhero thing to do. In a mighty display of divine power, Jesus strolls across the Sea of Galilee and then stills a strong wind. No wonder the disciples are terrified by the ghostly apparition coming toward them. Ghosts, after all, are spirits without flesh-and-blood bodies.
Physicist and theologian John Polkinghorne likens Jesus’ human/divine nature to the wave/particle duality of light. Light appears as a wave if one is asking “a wave-like question,” as a particle if one is asking “a particle-like question.” It’s not an either/or but a both/and. With respect to Jesus, ask a divine question and watch him walk on water and calm the seas. Ask a human question and watch John the Baptist fish Jesus out of the Jordan River; then watch this newly born man, still dripping wet, trudge into the wilderness to be tempted.