"The natural emotions are blameworthy and are like rust which deprives the heart of the bounties of God."

"Man possesses two kinds of susceptibilities: the natural emotions, which are like dust upon the mirror, and spiritual susceptibilities, which are merciful and heavenly characteristics.

There is a power which purifies the mirror from dust and transforms its reflection into intense brilliancy and radiance so that spiritual susceptibilities may chasten the hearts and heavenly bestowals sanctify them. What is the dust which obscures the mirror? It is attachment to the world, avarice, envy, love of luxury and comfort, haughtiness and self-desire; this is the dust which prevents reflection of the rays of the Sun of Reality in the mirror. The natural emotions are blameworthy and are like rust which deprives the heart of the bounties of God. But sincerity, justice, humility, severance, and love for the believers of God will purify the mirror and make it radiant with reflected rays from the Sun of Truth."

`Abdu'l-Bahá, The Promulgation of Universal Peace, p. 244

25 July 1912 
(excerpt from) Talk at Hotel Victoria 
Boston, Massachusetts