Covenant of Baha’u’llah
The Baha’i Faith began with the mission entrusted by God to two Divine Messengers—the Bab and Baha’u’llah. Today, the distinctive unity of the Faith They founded stems from explicit instructions given by Baha’u’llah that have assured the continuity of guidance following His passing. This line of succession, referred to as the Covenant, went from Baha’u’llah to His Son, ‘Abdu’l-Baha—the Centre of the Covenant.
Source: Bahá’í World Faith, 1976
O ye beloved of God, know that steadfastness and firmness in this new and wonderful Covenant is indeed the spirit that quickeneth the hearts which are overflowing with the love of the Glorious Lord; verily, it is the power which penetrates into the hearts of the people of the world! …
Were it not for the protecting power of the Covenant to guard the impregnable fort of the Cause of God, there would arise among the Baha’is, in one day, a thousand different sects as was the case in former ages. But in this Blessed Dispensation, for the sake of the permanency of the Cause of God and the avoidance of dissension amongst the people of God, the Blessed Beauty (may my soul be a sacrifice unto Him), has through the Supreme Pen written the Covenant and the Testament; He appointed a Center, the Exponent of the Book and the annuller of disputes. …
Praise be to God that the believers in America are steadfast but the firmer they are the better that no one might be able to intrude and introduce disputes, for disputes destroy the foundation of God’s Institution.
His Holiness Abraham, on Him be peace, made a covenant concerning His Holiness Moses and gave the glad-tidings of His coming. His Holiness Moses made a covenant concerning the Promised One, i.e. His Holiness Christ, and announced the good news of His Manifestation to the world. His Holiness Christ made a covenant concerning the Paraclete and gave the tidings of His coming. His Holiness the Prophet Muhammad made a covenant concerning His Holiness the Bab and the Bab was the One promised by Muhammad, for Muhammad gave the tidings of His coming. The Bab made a Covenant concerning the Blessed Beauty of Baha’u’llah and gave the glad-tidings of His coming for the Blessed Beauty was the One promised by His Holiness the Bab. Baha’u’llah made a covenant concerning a promised One who will become manifest after one thousand or thousands of years. He likewise, with His Supreme Pen, entered into a great Covenant and Testament with all the Baha’is whereby they were all commanded to follow the Center of the Covenant after His departure, and turn not away even to a hair’s breadth from obeying Him.