The moment we take our eyes off of Jesus is the moment we rely on our carnal/physical senses. What we see, hear, taste, smell, feel. That's when the enemy can attack us with doubt. Peter was walking on the water until he noticed the waves, took his eyes off of Jesus, and started to rationalize everything based off his carnal senses. Then, he sank. We need to do the opposite. The moment we notice the waves is the moment we NEED to focus on Jesus. We are to walk/live by faith and not by sight.