What will happen during the Formative and Golden Ages of the Faith – the Guardian explains

During this Formative Age of the Faith, and in the course of present and succeeding epochs, the last and crowning stage in the erection of the framework of the Administrative Order of the Faith of Bahá'u'lláh -- the election of the Universal House of Justice -- will have been completed, the Kitáb-i-Aqdas, the Mother-Book of His Revelation, will have been codified and its laws promulgated, the Lesser Peace will have been established, the unity of mankind will have been achieved and its maturity attained, the Plan conceived by 'Abdu'l-Bahá will have been executed, the emancipation of the Faith from the fetters of religious orthodoxy will have been effected, and its independent religious status will have been universally recognized, whilst in the course of the Golden Age, destined to consummate the Dispensation itself, the banner of the Most Great Peace, promised by its Author, will have been unfurled, the World Bahá'í Commonwealth will have emerged in the plenitude of its power and splendor, and the birth and efflorescence of a world civilization, the child of that Peace, will have conferred its inestimable blessings upon all mankind. 

- Shoghi Effendi  (‘The Challenging Requirements of the Present Hour, 5 June 1947’, ‘Citadel of Faith: Messages to America 1947-1957’; The Compilation of Compilations, vol. II, The Significance of the Formative Age of Our Faith)