The spirit of man is a circumambient power that encompasseth the realities of all things. Whatsoever thou dost see about thee — wondrous products of human workmanship, inventions, discoveries and like evidences — each one of these was once a secret hidden away in the realm of the unknown. The human spirit laid that secret bare, and drew it forth from the unseen into the visible world. There is, for example, the power of steam, and photography and the phonograph, and wireless telegraphy, and advances in mathematics: each and every one of these was once a mystery, a closely guarded secret, yet the human spirit unravelled these secrets and brought them out of the invisible into the light of day. Thus is it clear that the human spirit is an all-encompassing power that exerteth its dominion over the inner essences of all created things, uncovering the well kept mysteries of the phenomenal world.
The divine spirit, however, doth unveil divine realities and universal mysteries that lie within the spiritual world. It is my hope that thou wilt attain unto this divine spirit, so that thou mayest uncover the secrets of the other world, as well as the mysteries of the world below.
‘Abdu’l-Bahá