We should turn our back to darkness and our face to ‘Abdu’l-Baha

He [the Guardian] urges you to persevere and add up your accomplishments, rather than to dwell on the dark side of things. Everyone's life has both a dark and bright side. The Master said: turn your back to the darkness and your face to Me. (From a letter written on behalf of Shoghi Effendi, The Unfolding Destiny of the British Baha'i Community, p. 456)