In Ecclesiastes, Solomon said God made a time for everything in life and “set eternity in the hearts” of men (Eccl. 3:11).
So we know within us that all the times of life that He gives—of “birth and death,” “planting and uprooting,” “tearing down and building up,” “weeping and laughing,” “mourning and dancing,” “love and hate,” “war and peace,” and every other “purpose and event under heaven”—should mean something.
This “eternity in our hearts,” makes us crave lasting purpose and seek fulfillment. And it can’t be faked. We need it to be authentic.
But living in a fallen world “subjected to futility” (Rom. 8:20), where “all is vanity” (Eccl. 1:2,14; 3:19; 12:8). Even things that should be good and comforting to us are often just additional sources of frustration.
Augustine, summarized this great yearning within us, thwarted by life's futilities, as a “restlessness,” saying, “You have made us for yourself, O Lord, and our hearts are restless until they rest in You.”
Only in God and the things He gives—used properly for the purposes He gave them—can we hope to find the satisfaction, fulfillment, and contentment that our souls ache for.