The effect of backbiting on the heart of people

O beloved of the Lord! If any soul speak ill of an absent one, the only result will clearly be this: he will dampen the zeal of the friends and tend to make them indifferent. For backbiting is divisive, it is the leading cause among the friends of a disposition to withdraw. If any individual should speak ill of one who is absent, it is incumbent on his hearers, in a spiritual and friendly manner, to stop him, and say in effect: would this detraction serve any useful purpose? Would it please the Blessed Beauty, contribute to the lasting honour of the friends, promote the holy Faith, support the Covenant, or be of any possible benefit to any soul? No, never! On the contrary, it would make the dust to settle so thickly on the heart that the ears would hear no more, and the eyes would no longer behold the light of truth.

~ Abdu'l-Baha, Selections from the Writings of Abdu'l-Baha, p. 230


In the world of spirit there is no retrogression. The world of mortality is a world of contradictions, of opposites; motion being compulsory everything must either go forward or retreat. In the realm of spirit there is no retreat possible, all movement is bound to be towards a perfect state. 'Progress' is the expression of spirit in the world of matter. The intelligence of man, his reasoning powers, his knowledge, his scientific achievements, all these being manifestations of the spirit, partake of the inevitable law of spiritual progress and are, therefore, of necessity, immortal. My hope for you is that you will progress in the world of spirit, as well as in the world of matter; that your intelligence will develop, your knowledge will augment, and your understanding be widened.

~ Abdu'l-Baha, Paris Talks, p. 90


But on the other hand, when man does not open his mind and heart to the blessing of the spirit, but turns his soul towards the material side, towards the bodily part of his nature, then is he fallen from his high place and he becomes inferior to the inhabitants of the lower animal kingdom. In this case the man is in a sorry plight! For if the spiritual qualities of the soul, open to the breath of the Divine Spirit, are never used, they become atrophied, enfeebled, and at last incapable; whilst the soul's material qualities alone being exercised, they become terribly powerful -- and the unhappy, misguided man, becomes more savage, more unjust, more vile, more cruel, more malevolent than the lower animals themselves. All his aspirations and desires being strengthened by the lower side of the soul's nature, he becomes more and more brutal, until his whole being is in no way superior to that of the beasts that perish. Men such as this, plan to work evil, to hurt and to destroy; they are entirely without the spirit of Divine compassion, for the celestial quality of the soul has been dominated by that of the material. If, on the contrary, the spiritual nature of the soul has been so strengthened that it holds the material side in subjection, then does the man approach the Divine; his humanity becomes so glorified that the virtues of the Celestial Assembly are manifested in him; he radiates the Mercy of God, he stimulates the spiritual progress of mankind, for he becomes a lamp to show light on their path.

~ Abdu'l-Baha, Paris Talks, p. 97


I want to make you understand that material progress and spiritual progress are two very different things, and that only if material progress goes hand in hand with spirituality can any real progress come about, and the Most Great Peace reign in the world. If men followed the Holy Counsels and the Teachings of the Prophets, if Divine Light shone in all hearts and men were really religious, we should soon see peace on earth and the Kingdom of God among men. The laws of God may be likened unto the soul and material progress unto the body. If the body was not animated by the soul, it would cease to exist. It is my earnest prayer that spirituality may ever grow and increase in the world, so that customs may become enlightened and peace and concord may be established.

~ Abdu'l-Baha, Paris Talks, p. 107