We are challenged on every hand to work untiringly to achieve excellence in our lifework. Not all men are called to specialized or professional jobs; even fewer rise to the heights of genius in the arts and sciences; many are called to be laborers in factories, fields and streets. But no work is insignificant. All labor that uplifts should be undertaken with painstaking excellence. If a man is called to be a street sweeper he should sweep streets even as Michelangelo painted, or Beethoven composed music, or Shakespeare wrote poetry. He should sweep streets so well that all the hosts of heaven and earth will pause to say “Here lived a great street sweeper who did his job well.”

Martin Luther King, Jr. (1929-1968) American clergyman, civil rights leader, social activist, preacher
Sermon, New Covenant Baptist Church, Chicago (9 Apr 1967)