All humankind are like children in a school, and the Prophets and Manifestations of God as Teachers

O true companions! All humankind are as children in a school, and the Dawning-Points of Light, the Sources of divine revelation, are the teachers, wondrous and without peer. In the school of realities they educate these sons and daughters, according to teachings from God, and foster them in the bosom of grace, so that they may develop along every line, show forth the excellent gifts and blessings of the Lord, and combine human perfections; that they may advance in all aspects of human endeavour, whether outward or inward, hidden or visible, material or spiritual, until they make of this mortal world a wide-spread mirror, to reflect that other world which dieth not. (‘Abdu’l-Baha, The Compilation of Compilations vol. I, p. 269)