Bahá’u’lláh wrote:

“…All men have been created to carry forward an ever-advancing civilization…”
(Gleanings from the Writings of Bahá’u’lláh, p. 215)

‘Abdu’l-Bahá explained:

“All created things have their degree or stage of maturity. The period of maturity in the life of a tree is the time of its fruit-bearing…The animal attains a stage of full growth and completeness, and in the human kingdom man reaches his maturity when the light of his intelligence attains its greatest power and development… Similarly there are periods and stages in the collective life of humanity. At one time it was passing through its stage of childhood, at another its period of youth, but now it has entered its long-predicted phase of maturity, the evidences of which are everywhere apparent…That which was applicable to human needs during the early history of the race can neither meet nor satisfy the demands of this day, this period of newness and consummation. Humanity has emerged from its former state of limitation and preliminary training. Man must now become imbued with new virtues and powers, new moral standards, new capacities. New bounties, perfect bestowals, are awaiting and already descending upon him. The gifts and blessings of the period of youth, although timely and sufficient during the adolescence of mankind, are now incapable of meeting the requirements of its maturity.”
(Quoted in God Passes By, p. 164-165)