From a lecture by Rudolf Steiner at Dornach, Switzerland in 1923 – from the series Mystery Centres
http://wn.rsarchive.org/Lectures/GA232/English/GC1985/19231209p01.html:
And then, when the Mystery of Golgotha took place, when over in Palestine, the wonderful events came to pass which we describe as the experience of Christ Jesus on Golgotha and its surroundings, while these wonderful events came to pass in Palestine; great festivals were held [in Ireland] within the Hibernian Mysteries, and within their community, i.e. by the people who belonged to the Hibernian Mysteries.
And that which came to pass in actual fact in Palestine, was portrayed in pictures on the island of Hibernia in ways a hundred-fold, though the picture was as a memory of the past. They experienced in pictures the Mystery of Golgotha contemporaneously on the island of Hibernia, while the Mystery of Golgotha came to pass historically, in Palestine.
When later, in temples and churches, the Mystery of Golgotha was experienced pictorially, was shown in pictures to the people, then these were pictures which recalled something which had taken place on the earth, which were drawn out of the ordinary consciousness as a kind of historic memory.
These pictures existed on the island of Hibernia before they could be produced from historic memory of the past, but as they only could be produced out of the Spirit itself.
On the island of Hibernia that was spiritually seen which took place before the bodily eye in Palestine, at the beginning of our era.
And so, on the island of Hibernia, humanity actually experienced the Mystery of Golgotha spiritually. And this indicates the greatness of all that went forth later from the island of Hibernia, for the rest of the civilized world, but which vanished in later time.
**
As far as I can tell, Rudolf Steiner knew nothing substantive about Mormonism or The Book of Mormon. His teachings came from (or were confirmed by) a method he termed Spiritual Science or Clairvoyance (in the sense of clear-seeing).
This was a type of personal revelation, but not regarded as coming directly from God; rather it was more like being able to view or read objective knowledge of the totality of significant reality recorded objectively, and (he said) accessible to anyone ‘initiated’ in these methods (although this training included moral elements and pre-requisites, so was only possible for the worthy).
Anyway, this passage is interesting as describing an ancient Irish civilisation which – like the Nephites – was Christian before Christ, and which was aware of the events and significance of Christ’s ministry, death, resurrection and ascension.
(A major difference from the Nephites is that Steiner does not describe any visit to ancient Ireland by Christ himself. )
I personally suppose that this basic situation may well have happened in several places on earth – I mean that there may have been ancient societies (currently not known to history or archaeology) who knew of, and awaited the coming of Christ – and were spiritually aware (to varying degrees) of the nature of significance of the happenings in Palestine around AD 30-33 (or whenever precisely the ministry of Christ and his death occurred).