Adam Clarke on Ecclesiastes 3:22

A man should rejoice in his own works - Do not turn God's blessings into sin by perverseness and complaining; make the best of life. God will sweeten its bitters to you, if you be faithful. Remember this is the state to prepare for glory; and the evils of life may be so sanctified to you as to work for your good. Though even wretched without, you may be happy within; for God can make all grace to abound towards you. You may be happy if you please; cry to God, who never rejects the prayer of the humble, and gives his Holy Spirit to all them that ask him.