And a great windstorm arose, and the waves were breaking into the boat, so that the boat was already filling. But he was in the stern, asleep on the cushion. And they woke him and said to him, “Teacher, do you not care that we are perishing?” And he awoke and rebuked the wind and said to the sea, “Peace! Be still!” And the wind ceased, and there was a great calm. He said to them, “Why are you so afraid? Have you still no faith?”” (Mark 4:37–40, ESV)

I love the comment from the Bible Speaks Today commentary at this point:

They could hardly have been ready for the reply. ‘Why are you so afraid? Do you still have no faith?’ The crux of discipleship is located here. They needed him to do things: he wanted them to trust him. His very presence amongst them was all that they needed to survive.

Kristene DiMarco puts this verse into music in a stunningly beautiful way: