“Know that heaven and earth may pass away, but my words shall never pass away.”

"It is recorded in all the Books of the Gospel that He Who is the Spirit 13 spoke in words of pure light unto His disciples, saying: “Know that heaven and earth may pass away, but my words shall never pass away.” 14 As is clear and evident to thine eminence, these words outwardly mean that the Books of the Gospel will remain in the hands of people till the end of the world, that their laws shall not be abrogated, that their testimony shall not be abolished, and that all that hath been enjoined, prescribed, or ordained therein shall endure forever.

O My brother! Sanctify thy heart, illumine thy soul, and sharpen thy sight, that thou mayest perceive the sweet accents of the Birds of Heaven and the melodies of the Doves of Holiness warbling in the Kingdom of eternity, and perchance apprehend the inner meaning of these utterances and their hidden mysteries. For otherwise, wert thou to interpret these words according to their outward meaning, thou couldst never prove the truth of the Cause of Him Who came after Jesus, nor silence the opponents, nor prevail over the contending disbelievers. For the Christian divines use this verse to prove that the Gospel shall never be abrogated and that, even if all the signs recorded in their Books were fulfilled and the Promised One appeared, He would have no recourse but to rule the people according to the ordinances of the Gospel. They contend that if He were to manifest all the signs indicated in the Books, but decree aught besides that which Jesus had decreed, they would neither acknowledge nor follow Him, so clear and self-evident is this matter in their sight."

-Bahá'u'lláh, Gems of Divine Mysteries (Javáhiru’l-Asrár) , pp. 17-19



13. Jesus. 
14. cf. Matt. 24:35; Mark 13:31; Luke 21:33.