In these twelve men who came together to perform a special mission, the twelve different streams in the spiritual development of mankind were represented. The fact that all possible religions and all possible philosophies belong to the twelve basic types is in itself a mystery.
Buddhism, Brahmanism, Vedanta philosophy, materialism, or whatever it may be – all of them can be traced to the twelve basic types; it is just a matter of being quite exact. And so all the different streams of man’s spiritual life – the religions, the philosophies and world conceptions that are spread over the earth – were united in that council of the twelve.
After the period of darkness had passed and spiritual achievement was possible again, a thirteenth came in remarkable circumstances to the twelve. I am telling you now of one of those events which takes place secretly in the evolution of mankind once and once only. They cannot occur a second time and are mentioned not as an indication that efforts should be made to repeat them but for quite other reasons.
When the darkness had lifted and it was possible to develop clairvoyant vision again, the coming of the thirteenth was announced in a mysterious way to the twelve wise men. They knew that the time had come when a child with significant and remarkable incarnations behind him was to be born. Above all they knew that one of his incarnations had been at the time of the Mystery of Golgotha.
It was known, therefore, that one who had been a contemporary of the events in Palestine was returning. And the birth of the child in these unusual circumstances during the thirteenth century could not have been said to be that of a person of renown.
Rudolf Steiner, Intimate Workings of Karma