Walking on Water

And in the fourth watch [between 3:00--6:00 a.m.] of the night, Jesus came to them, walking on the sea. And when the disciples saw Him walking on the sea, they were terrified and said, it is a ghost! And they screamed out with fright. But instantly He spoke to them, saying, take courage! I AM [it is me]! Stop being afraid! And Peter answered Him, Lord; if it is You, command me to come to You on the water. He said, Come! So Peter got out of the boat and walked on the water, and he came toward Jesus. But when he perceived and felt the strong wind, he was frightened, and as he began to sink, he cried out, Lord, save me [from death]! Instantly Jesus reached out His hand and caught and held him, saying to him, O you of little faith, why did you doubt? And when they got into the boat, the wind ceased. Matthew 14:25-32
Peter walked on water with the sole purpose of going to Jesus. Christ told Peter come, not only so he would walk on the water, and thus know his Lord's power, but that he might know his own weakness. Now Peter had to step out of the boat *before* he could walk on the water. He had to have faith that if he put the sole of his foot onto the sea, he would not fall.

As soon as Peter began to doubt he began to fall. When we turn away from Christ, and look at the obstacles facing us, we will begin to fall; but when we call to him, he will stretch out his arm, and save us.