So when they had rowed about five and twenty or thirty furlongs, they saw Jesus walking on the sea, and drawing near unto the ship: and they were afraid.
All Commentaries on John 6:19 Go To John 6
Cyril of Alexandria
AD 444
When they are separated by great interval from the land, and it was like that they in their trouble would no way be saved (for they were now in the midst of the sea) then Christ thrice longed for appears to them. For thus could He give most welcome salvation to those in danger, when fear had already cut off all hope of life. But He appears to them miraculously (for so was it ordered to their greater profit) and they are astonished beholding Jesus going through the midst of the sea and upon the very waters, and make the miracle an addition to their fear. But Christ immediately relieves them from their misfortunes, saying, I am, be not afraid. For need, need must all disquiet be away, and they be openly superior to all danger, to whom Christ is now present. We shall see then by this again, that we ought to have a spirit courageous and manly in temptations, and endurance intense from hope in Christ, confirmed unto good confidence in our being surely saved, even though many be the fears of temptation that pour around us.
For observe that Christ does not appear to those in the boat immediately on their setting sail, nor at the commencement of their dangers, but when they are many furlongs off from the land. For not when the condition which harasses us first begins, does the grace of Him who saves visit us, but when the fear is at its height, and the danger now shews itself mighty, and we are found, so to say, in the midst of the waves of afflictions: then unlooked for does Christ appear, and puts away our fear, and will free us from all danger, by His Ineffable Power changing the dread things into joy, as it were a calm.