What does Mark 6:48 mean?
The evening that Jesus feeds the five thousand, He sends the Twelve ahead of Him to Capernaum while He goes to the mountains to pray. From this high vantage point, He can see the struggling boat four or five miles off. Although Luke mentions that they "sailed" to the Decapolis (Luke 8:23, 26), this may be a euphemism. There's no explicit indication this boat had a sail with which to tack against the wind. Or, the wind may be too strong for the fabric.The fourth watch is between three and six a.m. The Twelve had met up after their missions trip, rowed the boat the six miles from Capernaum to Bethsaida, spent the day watching Jesus heal people and listening to Him preach, passed out food in the afternoon, then returned to the boat to row it back to Capernaum. Now, they have been rowing for hours with little to show for it.
It's unclear why Jesus intends to pass them by. It could be that this is the Twelve's perception, not Jesus' intention. Or that Jesus plans to walk close enough for them to call out to Him. Some scholars believe that He means to emulate His pre-incarnate experiences with Moses (Exodus 33:19–23) and Elijah (1 Kings 19:11–12). Seeing the glory and power and dominion of Jesus should encourage the Twelve. Instead, it terrifies them and they mistake Him for a ghost (Mark 6:49).
God gave His prophets the ability to perform miracles in order to prove that their message was from Him. Common examples are healing, exorcising demons, and raising the dead. But there are a few miracles the Bible records only God being able to do. This includes walking on water (Job 9:8; Isaiah 43:16; 51:10; Habakkuk 3:15) and giving sight to the blind (Isaiah 42:5–7; Luke 4:16–19; Mark 8:22–26; 10:46–52).