Never. First, note that there is no definitive list of who is a manifestation of God.
“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.”
If such is the case, there should at least be agreement regarding each founder’s teachings on God. However, just the opposite is true.
- Krishna taught that God is pantheistic.
- Buddha was agnostic and indifferent to God’s existence.
- Muhammad was intensely monotheistic.
- And Jesus taught of a triune God.
Either these founders contradict each other (making it impossible to discern between a true founder and a false one), or the nature of God is contradictory (which is self-defeating and absurd), or the Baha’i Faith is false.
Further, by allowing these contradictory messages to be delivered by these “manifestations”, God Himself is culpable for all the religious wars between groups who follow one manifestation or another. Maybe our Baha’i friends can answer this question:
Why did God, in His infinite Wisdom and Omniscience, not foresee the possibility that followers of Muhammed would go to war with and kill the followers of the previous manifestation, Jesus?
The same may be said of Christian persecutions of the followers of another manifestation, Moses, of course.
Not only is there no official list of manifestations in the past, but there are more manifestations expected in the future…about one every thousand years or so:
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.
info.bahai.org/article-1-4-0-4.html