In plain words
From a cause arises the heavy bond of delusion; in delusion grows a foolish mind; in the foolish mind karma swells with pride; from the fruit of karma comes birth.
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The life of man is a mansion on four pillars: birth, karma, Dharma and Brahman. These four pillars rest on one another. They are bound together inseparably. Each of them depends on the other. What is birth for? For the doing of karma. What kind of karma must we do? We must do karma that is filled with Dharma. Through this karma filled with Dharma we must see Brahman. But today human birth has forgotten this goal. Karma is for the belly, Dharma for the world. The very thought of Brahman is nil. We cannot build even a small house without four walls. So for this building of life, these four, birth, karma, Dharma and Brahman, are like the walls that hold it up.
Then what is the cause of this birth? Karma alone is the cause of birth. What is karma? The energy of living. A body is the vehicle of this energy of life. In short, the body, the vehicle of life, is the karma-body, that is, nothing but a blend of karmas. Today we call every act a man does karma. Man does these karmas for the sake of some fruit. To experience this fruit he takes on a body. Hence: “Karmānu bandhini manuṣyaloke.” This whole world of men is bound by karma. We cannot keep away from karma. Everything is made of karma. So the doing of karma is essential. As the karmas we do, so the state we reach. As the action, so the habit. As the habit, so the conduct. As the conduct, so the future. That is why our actions must be good. All of life, all its good and bad, rests on karma. To think, “I am doing, I am experiencing, I am enjoying,” is the mark of Ahaṅkāra. Every good and every bad in a man's life rests on karma alone. Whether we know it or not, our actions are the result of karma.