As regards mankind in general perception of the spiritual world is of higher worth than non-perception. For one who is able to look into the spiritual world has intercourse with that world, he can teach not only men, but others, spiritual beings, and so further their development. Clairvoyant consciousness has therefore a quite special value, but for individuals knowledge only has value; and in respect of individual worth the clairvoyant does not differ from anyone else who only receives communications, and is himself unable to look into the spiritual world in any particular incarnation. Whatever we have received of spiritual truth is fruitful after death, no matter if we have beheld these truths ourselves or not.
Source: Rudolf Steiner – GA 124 – The Gospel According to St. Mark – The Ego – Lecture 3 – Berlin, 17th October 1910