A Covenant in the religious sense is a binding agreement between God and man, whereby God requires of man certain behaviour in return for which He guarantees certain blessings, or whereby He gives man certain bounties in return for which He takes from those who accept them an undertaking to behave in a certain way. There is, for example, the Greater Covenant which every Manifestation of God makes with His followers, promising that in the fulness of time a new Manifestation will be sent, and taking from them the undertaking to accept Him when this occurs. There is also the Lesser Covenant that a Manifestation of God makes with His followers that they will accept His appointed successor after Him. If they do so, the Faith can remain united and pure. If not, the Faith becomes divided and its force spent. It is a Covenant of this kind that Bahá’u’lláh made with His followers regarding ‘Abdu’l-Bahá and that ‘Abdu’l-Bahá perpetuated through the Administrative Order...
23 March 1975, from a letter written by the Universal House of Justice to an individual believer
The first duty prescribed by God for His servants is the recognition of Him Who is the Day Spring of His Revelation and the Fountain of His laws, Who representeth the Godhead in both the Kingdom of His Cause and the world of creation. Whoso achieveth this duty hath attained unto all good... It behoveth every one who reacheth this most sublime station, this summit of transcendent glory, to observe every ordinance of Him Who is the Desire of the world. These twin duties are inseparable. Neither is acceptable without the other....
They whom God hath endued with insight will readily recognize that the precepts laid down by God constitute the highest means for the maintenance of order in the world and the security of its! peoples.... Hasten to drink your fill, O men of understanding They that have violated the Covenant of God by breaking His commandments, and have turned back on their heels, these have erred grievously in the sight of God, the All-Possessing, the Most High.
“Gleanings from the Writings of Bahá’u’lláh”, #155, p. 330
Follow not, therefore, your earthly desires, and violate not the Covenant of God, nor break your pledge to Him. With firm determination, with the whole affection of your heart, and with the full force of your words, turn ye unto Him, and walk not in the ways of the foolish.... Break not the bond that uniteth you with your Creator, and be not of those that have erred and strayed from His ways....
“Gleanings from the Writings of Bahá’u’lláh” #153, p. 328
Great is thy blessedness inasmuch as thou hast been faithful to the Covenant of God and His Testament... Dedicate thyself to the service of the Cause of thy Lord, cherish His remembrance in thy heart and celebrate His praise in such wise that every wayward and heedless soul may thereby be roused from slumber.
“Tablets of Bahá’u’lláh Revealed after the Kitáb-i-Aqdas”, p. 262
...ye must conduct yourselves in such a manner that ye may stand out distinguished and brilliant as the sun among other souls. Should any one of you enter a city, he should become a centre of attraction by reason of his sincerity, his faithfulness and love, his honesty and fidelity, his truthfulness and loving-kindness towards all the peoples of the world, so that the people of that city may cry out and say:
“This man is unquestionably a Bahá’í, for his manners, his behaviour, his conduct, his morals, his nature, and disposition reflect the attributes of the Bahá’ís.” Not until ye attain this station can ye be said to have been faithful to the Covenant and Testament of God. For He hath, through irrefutable Texts, entered into a binding Covenant with us all, requiring us to act in accordance with His sacred instructions and counsels.
“Selections from the Writings of ‘Abdu’l-Bahá”, p. 71