It is true that real grace can suffer neither loss nor diminution, but its manifestations and its actings may. Who that possesses faith is not conscious that it ebbs and flows, rises and sinks, is strong and weak, and varies from day to day and from hour to hour? Thus when a sharp trial comes, its immediate effect is to depress faith. It falls upon it like a weight, and bends it down to the ground. Faith may be compared to the quicksilver in a weather-glass, or in a thermometer. The quantity of mercury in the bulb never varies; but it rises or falls in the tube, according to the weight of the air, or the heat of the day. Thus faith, though it abides in the heart without loss or diminution, yet rises or sinks in the feelings, as the weather is fair or foul, or as the sun shews or hides himself.
Did Job's faith, for instance, mount equally high when "in the days of his youth"—the spring of his soul—"the secret of God was upon his tabernacle," and when "he cursed his day," and cried, "O that I knew where I might find him?" Was Peter's faith as strong when he quailed before a servant girl as when he was ready to go to prison and to death? Or Abraham's when he denied Sarah to be his wife, and when with but three hundred and eighteen men he pursued and smote the army of four mighty kings?
If faith never fluctuates, never sinks and never rises, then we have at once the dead assurance of a professor; then faith is in our own keeping; then it does not hang on the smile or frown of God; then we are no more beggars and bankrupts, living on supplies given or withholden, but independent and self-sufficient; then we "have no changes, and so fear not God." But if faith ebb and flow, what is the cause? Is it in self? Can we add to its stature one cubit, or make one hair of it black or white? If not, then must its ebbings and flowings come from God.