I am going to ask you to study with me this morning the 73rd Psalm. Before I read the Psalm I had better tell you what it is about; then you will follow the line of thought in it with greater ease. The central faith of the Hebrew religion was that God governs this world according to the principles of morality, that He is on the side of goodness, and against wickedness. The facts of life clashed with that dogma of Hebrew faith. Good men in those old times found it as hard to believe in God and goodness as we do, and they got just as little, or just as much, supernatural help as we do. Therefore they could nowhere find an absolute certainty; they nowhere received from heaven a supernatural and complete explanation of the enigmas of life. God, because He loved them, deliberately left them to fight their battle for faith with the actual facts and the actual difficulties. He left them constantly trying to find a complete intellectual solution of the problem, and failing to do that, just as we fail; and so He shut them up to discovering a resting-place for faith in the heart when they could not get it in the head. A great many psalms have welled out of men's hearts, just like fountains away among the hills, and valleys, and slopes. This 73rd Psalm is brimful of human thoughts, and duties, and longings, pains, and battles, and victories, just like bits of your life when you were all alive to the real grandeur of your human existence, when your heart longed to think loftily of life, and to hold fast to God, and precisely because your heart was all alive you found it was not easy. I am going to ask you to follow this man's struggle against doubt, to watch the steps by which he descended into the valley of real questioning of God's goodness and of God's government of the world, and then to trace the steps by which he climbed back again to a hill-top of serene and tranquil certainty.