Ecclesiastes 3:10-12

I have seen the task which God has given to the sons of men with which to occupy themselves. He has made everything beautiful and appropriate in its time. He has also planted eternity [a sense of divine purpose] in the human heart [a mysterious longing which nothing under the sun can satisfy, except God]—yet man cannot find out (comprehend, grasp) what God has done (His overall plan) from the beginning to the end. I know that there is nothing better for them than to rejoice and to do good as long as they live