Jesus Walks on Water
"While Jesus leaves for the mountains of upper Galilee, the disciples set sail, heading for the lake’s northeast shore. After rowing three or four miles, a storm catches them in the middle of the lake. As noted above, such east/west winds are common on this sea, and fishermen watched for them carefully. Their fear of the rough water, however, was surpassed by their terror at seeing Jesus walking to them on the water (6:19). Again, we have another motif from the Old Testament—a water miracle—that reminds us of the moment when Moses led Israel through the water (Ex. 13–15). Psalm 77 describes this moment in Israel’s life and explains that it was in fact God who led them.
The waters saw you, O God,
the waters saw you and writhed;
the very depths were convulsed.…
Your path led through the sea,
your way through the mighty waters,
though your footprints were not seen.
You led your people like a flock
by the hand of Moses and Aaron. (Ps. 77:16, 19–20)" 
Jesus has already offered proof that He is God: the approval of the Father, the witness of the Old Testament, miracles of healing, and more. Here is yet another proof: He is in command of creation. Who else is in command except Him who created? No one.