Spiritual science can be understood by every person who wants to understand its findings. It strives to give people what each individual soul can truly achieve on its own, not by following the religious founders, as in earlier times. And although it must be individual researchers who make the results of this science of the spirit available today, they do so in a form that can be understood by everyone who wants to. I have often emphasized that it is a complete misunderstanding to say spiritual science must also be believed. When people say this, it is because they are so crammed full with materialistic prejudices that they do not look at what spiritual science really has to offer. As soon as it is examined, everything becomes understandable. One does not need clairvoyance for this; our ordinary understanding is enough to really grasp and comprehend all this gradually — of course, “gradually” will be inconvenient for some people.
Source: Rudolf Steiner – GA 154 – The Presence of the Dead on the Spiritual Path: Lecture I: Understanding the Spiritual World (Part 1) – Berlin, April 18, 1914
Translated by Christian von Arnim