December 29

We cannot segregate the human heart from the environment outside us and say that once one of these is reformed everything will be improved. Man is organic with the world. His inner life moulds the environment and is itself also deeply affected by it. The one acts upon the other and every abiding change in the life of man is the result of these mutual reactions.

No movement in the world directs its attention upon both these aspects of human life and has full measures for their improvement save the teachings of Bahá'u'lláh. And this is its distinctive feature. If we desire therefore the good of the world we should strive to spread those teachings and also practice them in our own life. Through them will the human heart be changed and also our social environment provides the atmosphere in which we can grow spiritually and reflect in full the light of God shining through the revelation of Bahá'u'lláh. 
- Shoghi Effendi  (From letter dated 17 February 1933 written on behalf of Shoghi Effendi to an individual believer; The Compilation of Compilations, Vol. 3, Social and Economic Development)