If you roll a ball down a level street, it doesn't roll endlessly for mile after mile but stops in a block or two because of friction acting against its motion. Likewise, for life to be perpetual or eternal it must be free from the abrasive effects of impatience, stress, anxiety, displeasure, and insecurity. Such negative elements can work against life until it comes to the dismal halt of aging and death.
Of course, in the absolute sense, nothing can oppose the activity of Life, God. "Mind is the source of all movement," writes Mrs. Eddy, "and there is no inertia to retard or check its perpetual and harmonious action." In the same paragraph she goes on, "Matter and its effects—sin, sickness, and death—are states of mortal mind which act, react, and then come to a stop." Science and Health, p. 283.
True existence is the divine Mind, God, and His expression. Mind is represented through its ideas, and Mind governs all perfectly. The human picture may be one of clashing personalities or circumstances, but as we perceive that man actually lives within the operation of God's law, freedom is restored. Discernment of the unrestricted nature of being is essential as one awakes to eternal life.