Bahá'u'lláh is the Universal Manifestation of God for this Day and the Author of the Bahá'í Revelation. His Laws and Teachings embodied in His written Works are unreservedly accepted as the revealed Word of God.
Bahá'u'lláh made a binding and indestructible Covenant with His followers in a written Will and Testament (Kitáb-i-Ahd), also designated by Him as the "Book of My Covenant", in which they were enjoined to turn to His eldest son, 'Abdu'l-Bahá, the "most great Branch", after His ascension. 'Abdu'l-Bahá's station was further confirmed in the Tablet of the Branch (Súriy-i-Ghusn) penned by Bahá'u'lláh in which 'Abdu'l-Bahá was referred to as "this sacred and glorious Being"...."this Branch of Holiness" and the "Limb of the Law of God." By virtue of this divine appointment, 'Abdu'l-Bahá is recognized as the Center of Bahá'u'lláh's Covenant, His vicegerent on earth, the Executive of His authority, the Interpreter of His mind, the Focal Point of His unerring guidance, the Exemplar of His Faith and the Architect of His World Order.
The world Order of Baha’u’llah Continues to Unfold Written by:
Joel Bray Marangella, the Third Guardian of Bahai Faith, Page No.79