"Then he got into the boat and his disciples followed him. Suddenly a furious storm came up on the lake, so that the waves swept over the boat. But Jesus was sleeping." NIV translation
The lake that is mentioned here is the Sea of Galilee (Lake Kineret) and to understand this passage we need to know a little more about the lake and its surrounding area. The lake itself is rather small and shallow (its deepest part is about 200 feet) even though it is Israel's largest body of fresh water. It is like a bowl as there are mountains around it and the surface of the lake is about 680 feet below sea level elevation. This type of geography is ripe for producing sudden severe storms due to the cool mountain air flowing down to meet the warm, moist air from the lake. This physical setting is a perfect location for teaching about the battle between the flesh and the spirit.
We remember that, prior to this trip across the lake, Jesus had went up on a mountain to teach about the kingdom of God. Now, they are in the process of crossing the lake and heading over to a Gentile area.
So, what does all of this have to do with being a follower (disciple) of Jesus Christ and a member of the kingdom of heaven?
As we saw, mountains were considered places of learning (especially the teaching of the patriarchs) and the mountains to the east of the lake are really tall at about 2000 feet. The wind (teaching) that flowed from that mountain produced the storm that the people in the boat were now facing. This storm is a picture of the battle between the flesh and the spirit or religion (Law) and grace.
Just prior to getting in the boat, Jesus had urged a teacher of the law and even one of His own disciples to abandon their false religion in order to follow Him. We see that Jesus was sleeping in the boat and that is a picture of confident peace which is through Him alone. Religion (from the mountain of the patriarchs) teaches that man must work to achieve the security that allows us to sleep in peace while Jesus taught that faith (trust) in Him produces peace in us. Much like the warm and cold airstreams above the lake, they cannot remain in the same place without a storm (battle) taking place.