Apparently Peter had forgotten, for the moment, the wind and the waves. As his feet became accustomed to walking on the surface of the water he evidently thought of his companions in the boat, and wondered what they thought of his new-found skill. Turning his glance momentarily back to the boat, he lost sight of Jesus. At that moment he was in the trough between two waves, and when he returned his gaze again to where Jesus had been he could no longer see Him (see DA 381). All he could see was the turbulent water and the wind. In that brief instant self-satisfaction had diluted faith with pride, so to speak, and faith lost its sustaining power.
He was afraid.
We need never fear so long as we keep our eyes upon Jesus and trust in His grace and power, but when we turn our gaze upon self and upon others we have good reason to be afraid.
Beginning to sink.
A fisherman all his life, Peter knew how to swim (see John 21:7). But a sea like this, in which a boat was not safe, was even less safe for a swimmer.
Save me.
The form of the verb used in the Greek implies the urgency of Peter’s appeal.