It is better to light a candle than to curse the darkness.

W. L. Watkinson (1838–1925) English Methodist minister and preacher [William Lonsdale Watkinson]

Sermon (1907), “The Invincible Strategy,” The Supreme Conquest and other Sermons Preached in America, Sermon 14
    (Source)

The sermon was written around Romans 12:21 ("Be not overcome of evil, but overcome evil with good.").

Often attributed as a Chinese proverb, or a quotation from Confucius or Eleanor Roosevelt.

For more information on this quote's origin and variations, see:

• Quote Origin: Better to Light a Candle Than to Curse the Darkness – Quote Investigator®
• Eleanor Roosevelt: "It's Better to Light a Candle than to Curse the Darkness." Quote or No Quote? Professor Buzzkill

See also Kennedy (1960), Pratchett (1993), and Carlin (2004).