A.W. Tozer gives a helpful picture of God’s sovereignty:
Man’s will is free because God is sovereign….Perhaps a homely illustration might help us to understand.
An ocean liner leaves New York bound for Liverpool. Its destination has been determined by proper authorities. Nothing can change it. This is at least a faint picture of sovereignty.
On board the liner are several scores of passengers. These are not in chains, neither are their activities determined for them by decree. They are completely free to move about as they will. They eat, sleep, play, lounge about on the deck, read, talk, altogether as they please; but all the while the great liner is carrying them steadily onward toward a predetermined port.
Both freedom and sovereignty are present here and they do not contradict each other. So it is, I believe, with man’s freedom and the sovereignty of God. The mighty liner of God’s sovereign design keeps its steady course over the sea of history. God moves undisturbed and unhindered toward the fulfillment of those eternal purposes which He purposed in Christ Jesus before the world began. We do not know all that is included in those purposes, but enough has been disclosed to furnish us with a broad outline of things to come and to give us good hope and firm assurance of future well-being.
Paul reminds us in 1 Corinthians 16:13 to “Be on guard. Stand firm in the faith. Be courageous. Be strong.” But we need not fear the future. God is in control of our ship.