Comprehension of Anthroposophy is open to anyone
That Steiner considered Anthroposophy - the results of his spiritual research - accessible to anyone is evident in the following quotes:
"These facts [spiritual truths] have been investigated and communicated, and they can be grasped by healthy human intelligence, if this healthy intelligence will be unprejudiced enough not to base its conclusions wholly on what goes by the name of proof, logical deduction, and the like, in regard to the outer sense world. On account of these hindrances it is frequently stated that unless someone is able oneself to investigate supersensible worlds, one cannot understand the results of supersensible research." (Page 81)
"Once again I would like to emphasize: if these things are investigated, everyone who approaches the results with an unprejudiced mind can understand them with ordinary, healthy human reason ?just as he can understand what astronomers or biologists have to say about the world. The results can be tested, and indeed one will find that this testing is the first stage of initiation-knowledge. For initiation-knowledge, one must first have an inclination towards truth, because truth not untruth and error, is one's object." (Page 101)
Rudolf Steiner. "Esoteric Development." New York: Anthroposophic Press, 1982. From GA 305, Lecture of 20 Sep 1922.