Posted every second day…

January 12

The most important thing is to polish the mirrors of hearts in order that they may become illumined and receptive of the divine light. One heart may possess the capacity of the polished mirror; another, be covered and obscured by the dust and dross of this world. Although the same Sun is shining upon both, in the mirror which is polished, pure and sanctified you may behold the Sun in all its fullness, glory and power, revealing its majesty and effulgence; but in the mirror which is rusted and obscured there is no capacity for reflection, although so far as the Sun itself is concerned it is shining thereon and is neither lessened nor deprived. Therefore, our duty lies in seeking to polish the mirrors of our hearts in order that we shall become reflectors of that light and recipients of the divine bounties which may be fully revealed through them. 
(‘Abdu’l-Baha, from a talk, New York, 14 April 1912; ‘The Promulgation of Universal Peace: Talks Delivered by 'Abdu'l-Bahá during His Visit to the United States and Canada in 1912’)