“…The next time we are tempted let us remember this man Peter, who should never have looked at the waves at all. Why not? For this reason, that he had already settled the question before he went out of the boat! …He knew the boat was tossing, and so, when he made that statement to our Lord it means that he said to Him: I don’t care what the sea is doing. He had got above it, he had solved the problem, and so he had gone out of the boat and was walking on the sea. There was nothing new about the waves, there was no new factor. He was not confronted by any sort of new problem. The Lord Jesus Christ was actually enabling him to walk on turbulent waves. Well, why then look at them? What reason was there for doing so? None at all. It was ridiculous, it was foolish.
That is always the trouble with weak faith, it comes back again to questions which it has already solved and answered. If you have ever believed on the Lord Jesus Christ, you must, in some shape or form, have met with and dealt with the difficulties or you would not have arrived at faith. Well, why go back? It is sheer folly. Not only is it a matter of unbelief, it is a question of conduct and behavior. Why sit down and face troubles again that you have already met and solved before you stepped out of the boat?...There was no excuse for him, there was nothing new for him to consider. It is of the essence of faith to refuse after-thoughts. Reject them, have nothing to do with them. Say to them, ‘I have already dealt with you!’” ~ Martyn Lloyd-Jones