Ecclesiastes 3:9-14 NIV
What do workers gain from their toil? I have seen the burden God has laid on the human race. He has made everything beautiful in its time. He has also set eternity in the human heart; yet no one can fathom what God has done from beginning to end. I know that there is nothing better for people than to be happy and to do good while they live. That each of them may eat and drink, and find satisfaction in all their toil—this is the gift of God. I know that everything God does will endure forever; nothing can be added to it and nothing taken from it. God does it so that people will fear him.
NIV: New International Version