Bahá’í Sacred Writings, ‘Abdu’l-Bahá, #319

Absolute repose does not exist in nature. All things either make progress or lose ground. Everything moves forward or backward, nothing is without motion. From his birth, a man progresses physically until he reaches maturity, then, having arrived at the prime of his life, he begins to decline, the strength and powers of his body decrease, and he gradually arrives at the hour of death. Likewise a plant progresses from the seed to maturity, then its life begins to lessen until it fades and dies. A bird soars to a certain height and having reached the highest possible point in its flight, begins its descent to earth.

Thus it is evident that movement is essential to all existence. All material things progress to a certain point, then begin to decline. This is the law which governs the whole physical creation.

Now let us consider the soul. We have seen that movement is essential to existence; nothing that has life is without motion. All creation, whether of the mineral, vegetable or animal kingdom, is compelled to obey the law of motion; it must either ascend or descend. But with the human soul, there is no decline. Its only movement is towards perfection; growth and progress alone constitute the motion of the soul.

Divine perfection is infinite, therefore the progress of the soul is also infinite. From the very birth of a human being the soul progresses, the intellect grows and knowledge increases. When the body dies the soul lives on. All the differing degrees of created physical beings are limited, but the soul is limitless!…

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.

You must ever press forward, never standing still; avoid stagnation, the first step to a backward movement, to decay.