Here is a great quote by A.W. Tozer on the sovereignty of God:
God sovereignly decreed that man should be free to exercise moral choice, and man from the beginning has fulfilled that decree by making his choice between good and evil. When he chooses to do evil, he does not thereby countervail the sovereign will of God but fulfills it, inasmuch as the eternal decree decided not which choice the man should make but that he should be free to make it. If in His absolute freedom God has willed to give man limited freedom, who is there to stay His hand or say, “What doest thou?” Man’s will is free because God is sovereign. A God less than sovereign could not bestow moral freedom upon His creatures. He would be afraid to do so.
A.W. Tozer, The Knowledge of the Holy, chapter 22 “The Sovereignty of God”. (book can be found online here)