The human passions are like water: left unconfined, their tendency is always downward. You can carry water upward or force it upward with a pump, but in order to do so you must confine it in a vessel or a pipe. The moment it gains its liberty by breaking through the barrier, it rushes downward. So the human passions and propensities must be kept confined by the will. When they are not, they carry the whole man downward. By the power of our wills we may raise ourselves to higher altitudes, to greater heights of morality; but the moment the will weakens so that passion breaks through, the course is immediately downward. Water is raised to heights by great labor; so we reach morality only by the greatest efforts, and maintain it only by careful watchfulness and stedfast purpose.
But the sun, with its warming rays, smiles down upon the water, and the water rises in unseen vapor and floats into the atmosphere. There is no struggle and terrible compulsion and repression, but only silence, calmness, and peace. When it rises from the muddy pool, the stagnant pond, or the filthy gutter, it rises pure and clean, leaving behind the mud, the slime, the offensive odors, the noxious germs and bacteria. So when the sunshine of God's love shines upon and warms our hearts, it lifts us up from all the slime and filth of sinful habits, clean and pure, into heavenly places in Christ Jesus.
So long as the water is kept warm, it floats onward; but when it cools, it condenses and falls back again, perhaps into the same slimy pool. Likewise, so long as our hearts are kept warm by the rays of God's love shining therein, our pure moral state is easily maintained; but when we lose the warmth of that love, lower things begin to attract us and soon we fall down toward the former level. Keep your heart ever turned toward the Sun of Righteousness, cherish its soul-warming rays of love, and you will float on the atmosphere of heaven far above the things of sin.