Eccelesiastes

He has made everything beautiful in its time. Also, he has put eternity into man’s heart, yet so that he cannot find out what God has done from the beginning to the end.  (Ecclesiastes 3:11)

Behold, what I have seen to be good and fitting is to eat and drink and find enjoyment in all the toil with which one toils under the sun the few days of his life that God has given him, for this is his lot.  (Ecclesiastes 5:18)

The end of the matter; all has been heard. Fear God and keep his commandments, for this is the whole duty of man.  (Ecclesiastes 12:13 )