Once the water is still, Jesus speaks to his disciples. He rebukes them for their fear and lack of faith. Clearly, Jesus expected his disciples to act differently than the way they did. Having seen the miracles that he has performed and heard the words that he has spoken about himself (Son of Man, Lord of the Sabbath), they should have known that he has the ability to act with divine power. Jesus is therefore rebuking them for being so frightened when they know that he is with them in the boat and has the power to protect them. They panicked where they had no need to panic. They are thus being rebuked not because they asked Jesus for help (which was the right thing to do) but because they panicked in the midst of the storm rather than having the confident assurance that they were with Jesus and he would be able to care for them.
40 He said to them, “Why are you so afraid? Have you still no faith?”