Jesus fed the five thousand on the east side of the Sea of Galilee, and soon afterward He delivered His Bread of Life Discourse in Capernaum, which was on the west coast of the sea (John 6:1–14, 24). Today’s passage describes how He and His disciples moved from one location to the other.
Initially, the disciples set out to cross the sea independently of Jesus. Our Lord had withdrawn to the mountain, and the disciples set out by boat for Capernaum before Jesus returned to them (vv. 15–17). Geographically, the Sea of Galilee sits about six hundred feet below sea level, and the movement of air over the sea commonly results in violent and terrifying storms. Apparently, this is what happened when the disciples were rowing across the body of water, for a strong storm made the sea rough (v. 18). We should not quickly pass over this detail, for even the most seasoned seafarer could run into trouble when a storm broke out over the sea.
However, it was not the tremendous storm that caused the disciples the greatest fear. During the storm, they saw Jesus walking on the very sea itself, not being tossed and turned by the waves, and they became frightened (v. 19). The disciples saw on this occasion a glimpse of Jesus’ deity, for who can walk on water? What is more, the ancient Jews regarded the sea as a terrifying enemy, unpredictable and something that only God could tame (Job 38:8–11). But when Jesus walked on the water and approached the boat, the storm immediately subsided and the sea became calm (John 6:19–21). Clearly, the disciples were dealing with more than a mere man.
Jesus’ own words to the disciples upon reaching the boat help confirm this. Our Lord told them not to fear. “It is I,” Jesus said, which translates the phrase eg eimi , the Greek version of God’s covenantal name I am. As we will see, this phrase appears frequently on the lips of Jesus in John’s gospel, and it is a particularly strong hint at our Lord’s deity. Jesus did things that only God can do and made claims that only God can make. This has applications for how we understand the true identity of Jesus.
After Jesus entered the boat, we read in verse 21 that the boat immediately reached the shore. This may suggest a miracle of some kind that caused it to travel several miles in only seconds, but in any case, ministry in Capernaum would soon begin in earnest.