9 Well, brethren, my sermon must be ended. Consider the world to be the sea; the wind is boisterous, and there is a mighty tempest. Each man's peculiar lust is his tempest. Thou dost love God; you walk upon the sea, and under your feet is the swelling of the world. Thou dost love the world, it will swallow you up. It skills only how to devour its lovers, not to carry them. But when your heart is tossed about by lust, in order that you may get the better of your lust, call upon the Divinity of Christ.
Think ye that the wind is then contrary, when there is this life's adversity? For so when there are wars, when there is tumult, when there is famine, when there is pestilence, when even to every individual man his private calamity arrives, then the wind is thought to be contrary, then it is thought that God must be called upon. But when the world wears her smile of temporal happiness, it is as if there were no contrary wind. But do not ask upon this matter the tranquil state of the times: ask only your own lust.
See if there be tranquillity within you: see if there be no inner wind which overturns you; see to this. There needs great virtue to struggle with happiness, lest this very happiness allure, corrupt, and overthrow you. There needs, I say, great virtue to struggle with happiness, and great happiness not to be overcome by happiness. Learn then to tread upon the world; remember to trust in Christ. And “if your foot have slipped;” if you totter, if some things there are which you can not overcome, if you begin to sink, say, “Lord, I perish, save me.” Say, “I perish,” that you perish not. For He only can deliver you from the death of the body, who died in the body for you. Let us turn to the Lord, etc.
Source: Sermons on Selected Lessons of the New Testament (New Advent)