Walking on the water is often a saying that tries to express the special feeling or extraordinary thing that has been done. Jesus also walked on the water.
Friends of Jesus were in a boat on the sea of Galilee and were stuck in a heavy storm. Struggling with the weather and the water, they encountered a ghost and became very afraid.
Well, the friends of Jesus thought it was a ghost, but actually, it was Jesus walking on the water to silence the storm. Peter dared to walk on the water too but wasn’t able to keep walking because of fear of the wind and the waves.