From the Mahabharata.

Heed how thou livest. Do no act by day
Which from the night shall drive thy peace away.
In months of sun so live that months of rain
Shall still be happy. Evermore restrain
Evil and cherish good, so shall there be
Another and a happier life for thee.

John Greenleaf Whittier

http://www.poemhunter.com/poem/conduct-3/