The Oneness of Religion

The principle of the unity of religion is at the center of Bahá'í teachings. Bahá'u'lláh states that humanity is engaged in a collective growth process quite similar to the growth process of an individual: just as a person begins life as a helpless infant and attains maturity in successive stages, so humankind began its collective social life in a primitive state, gradually attaining maturity. In the case of the individual, it is clear that his or her development takes place as a result of the education he or she receives from parents, teachers, and society in general. But what is the motive force in humankind's collective evolution?
The answer the Bahá'í Faith provides to this question is "revealed religion." In one of His major works, the Kitab-i-Iqan (the Book of Certitude), Bahá'u'lláh explained that God, the Creator, has intervened and will continue to intervene in human history by means of chosen Messengers. These Messengers, Whom Bahá'u'lláh called "Manifestations of God ," are principally the Founders of the major revealed religions, such as Abraham, Moses, Buddha, Zoroaster, Jesus, Muhammad, and so forth. It is the spirit released by the coming of these Manifestations, together with the influence of Their teachings and the social systems established by Their laws and precepts, that enable humankind to progress in its collective evolution. Simply put: the Manifestations of God are the chief educators of humanity. With regard to the various religious systems that have appeared in human history, Bahá'u'lláh has said:
These principles and laws, these firmly-established and mighty systems, have proceeded from one Source and are the rays of one Light. That they differ one from another is to be attributed to the varying requirements of the ages in which they were promulgated.2
Thus the principle of the unity of religion means that all of the great religious Founders--the Manifestations--have come from God, and that all of the religious systems established by Them are part of a single divine plan directed by God.
In reality, there is only one religion, the religion of God. This one religion is continually evolving, and each particular religious system represents a stage in the evolution of the whole. The Bahá'í Faith represents the current stage in the evolution of religion. To emphasize the idea that all of the teachings and actions of the Manifestation are directed by God and do not originate from natural, human sources, Bahá'u'lláh used the term "revelation" to describe the phenomenon that occurs each time a Manifestation appears. In particular, the writings of the Manifestation represent the infallible Word of God. Because these writings remain long after the earthly life of the Manifestation is finished, they constitute an especially important part of the phenomenon of revelation. So much is this so, that the term "revelation" is sometimes used in a restricted sense to refer to the writings and words of the Manifestation.
Religious history is seen as a succession of revelations from God and the term "progressive revelation" is used to describe this process. Thus, according to Bahá'ís, progressive revelation is the motive force of human progress, and the Manifestation Bahá'u'lláh is the most recent instance of revelation.
Bahá'u'lláh taught that the time interval between two Manifestations may be about one thousand years. He also taught that the process of revelation will not stop with His revelation and that another Manifestation will come after Him, though not before the expiration of one thousand years from Bahá'u'lláh's coming. According to the Bahá'í writings, the process of revelation will continue indefinitely into the future and humankind will see the coming of a great many more Manifestations.
To put the Bahá'í concept of religion more clearly in focus, let us compare it with some other ways in which religion has been regarded. On one hand is the view that the various religious systems result from human striving after truth. In this conception, the Founders of the great religions do not reveal God to us, but are rather philosophers or thinkers, human beings who may have progressed farther than others in the discovery of truth. This notion excludes the idea of a basic unity of religion since the various religious systems are seen as representing different opinions and beliefs arrived at by fallible human beings rather than infallible revelations of truth from a single source.
Many orthodox adherents of various religious traditions, on the other hand, argue that the Prophet or Founder of their particular tradition represents a true revelation of God to humanity, but that the other religious Founders are false prophets, or at least essentially inferior to the Founder of the tradition in question. For example, many Jews believe that Moses was a true Messenger of God, but that Jesus was not. Similarly, many Christians believe in Jesus' revelation, but consider that Muhammad was a false prophet, and hold that Moses was inferior in status to Christ.
The Bahá'í principle of the oneness of religion differs fundamentally from both of these traditional concepts. Bahá'u'lláh attributed the differences in some teachings of the great religions not to any human fallibility of the Founders, but rather to the different requirements of the ages in which the revelations occurred. In addition, He maintained that there has been a great deal of human error introduced into religion through the corruption of texts and the addition of extraneous ideas. Moreover, Bahá'ís consider that no one of the Founders is superior to another. Shoghi Effendi has summarized this view in the following words:
The fundamental principle enunciated by Bahá'u'lláh, the followers of His Faith firmly believe, is that religious truth is not absolute but relative, that Divine Revelation is a continuous and progressive process, that all the great religions of the world are divine in origin, that their basic principles are in complete harmony, that their aims and purposes are one and the same, that their teachings are but facets of one truth, that their functions are complementary, that they differ only in the nonessential aspects of their doctrines, and that their missions represent successive stages in the spiritual evolution of human society.3
'The Changeless Faith of God'
Adapted from William S. Hatcher and J.Douglas Martin, The Bahá'í Faith: The Emerging Global Religion (San Francisco: Harper and Row, 1985), pp. 81-84.
Bahá'u'lláh, Gleanings from the Writings of Bahá'u'lláh, 2d. rev. ed. (Wilmette: Bahá'í Publishing Trust, 1976), pp. 287-88.
Shoghi Effendi, "The Faith of Bahá'u'lláh" in World Order, Vol. 7, No. 2 (1972-73), p. 7.