Drawing on a concept that may have first appeared in a work of fiction ,
Steiner taught that in order to enter the spirit world we must pass a terrible specter:
the Guardian of the Threshold.
Actually, Steiner said, there are two such guardians.
Here are some of his statements on this matter.
"In our life in the physical world of the senses, the double [i.e., our lower self]  immediately makes itself invisible by means of the sense of shame ... Simultaneously, however, the double also conceals [the spirit realm]. It stands like a guardian in front of that world, refusing entry to anyone not yet suitable for entering. The double can therefore be called ‘the guardian of the threshold to the world of soul and spirit.’ We encounter this guardian of the threshold not only when we enter the supersensible world in the way described [i.e., while still alive] but also when we enter it through physical death. The guardian reveals itself gradually in the course of our soul-spiritual development between death and a new birth. In this case, however, we are not oppressed by this encounter because we know about worlds we did not know about during life between birth and death.
"If we were to enter the world of soul and spirit without encountering the guardian of the threshold, we would succumb to one deception after another, because we would never be able to distinguish between what we ourselves were bringing into this world and what really belongs to it." — Rudolf Steiner, AN OUTLINE OF ESOTERIC SCIENCE (Anthroposophic Press, 1997), p. 361.
“The important experiences marking the [esoteric] student's ascent into the higher worlds include his meeting with the Guardian of the Threshold. Strictly speaking, there are two Guardians: a lesser and a greater. The student meets the lesser Guardian when the threads connecting willing, feeling, and thinking within the finer astral and etheric bodies begin to loosen ... The greater Guardian is encountered when this sundering of the connections extends to the physical parts of the body, that is, at first to the brain. The lesser Guardian is a sovereign being. He does not come into existence, as far as the student is concerned, until the latter has reached the requisite stage of development ... [He is a] A truly terrible spectral being.” — Rudolf Steiner, KNOWLEDGE OF THE HIGHER WORLDS AND ITS ATTAINMENT (Anthroposophic Press, 1947), chapter 10, GA 10.
“What is here indicated in narrative form must not be understood in the sense of an allegory, but as an experience of the highest possible reality befalling the esoteric student.
“The [lesser] Guardian must warn him not to go a step further unless he feels in himself the strength to fulfill the demands made in the above speech. However horrible the form assumed by the Guardian, it is only the effect of the student's own past life, his own character risen out of him into independent existence. This awakening is brought about by the separation of will, thought, and feeling. To feel for the first time that one has oneself called a spiritual being into existence is in itself an experience of deepest significance. The student's preparation must aim at enabling him to endure the terrible sight without a trace of timidity and, at the moment of the meeting, to feel his strength so increased that he can undertake fully conscious the responsibility for transforming and beautifying the Guardian.
“If successful, this meeting with the Guardian results in the student's next physical death being an entirely different event from the death as he knew it formerly. He experiences death consciously by laying aside the physical body as one discards a garment that is worn out or perhaps rendered useless through a sudden rent. Thus his physical death is of special importance only for those living with him, whose perception is still restricted to the world of the senses. For them the student dies; but for himself nothing of importance is changed in his whole environment. The entire supersensible world stood open to him before his death, and it is this same world that now confronts him after death.” — Ibid.
“Now in the Guardian of the Threshold as described above, the product of the past is manifest, containing only so many seeds of the future as could be planted in the course of time. Yet everything that can be extracted from the sense-world must be carried into the supersensible world. Were man to bring with him only what had been woven into his counterpart out of the past, his earthly task would remain but partially accomplished. For this reason the lesser Guardian of the Threshold is joined, after a time, by the greater Guardian. The meeting with the second Guardian will again be described in narrative form.
When the student has recognized all the elements from which he must liberate himself, his way is barred by a sublime luminous being whose beauty is difficult to describe in the words of human language. This encounter takes place when the sundering of the organs of thinking, feeling, and willing extends to the physical body, so that their reciprocal connection is no longer regulated by themselves but by the higher consciousness, which has now entirely liberated itself from physical conditions. The organs of thinking, feeling and willing will then be controlled from supersensible regions as instruments in the power of the human soul. The latter, thus liberated from all physical bonds, is now confronted by the second Guardian of the Threshold who speaks as follows:
“Thou hast released thyself from the world of the senses. Thou hast won the right to become a citizen of the supersensible world, whence thine activity can now be directed. For thine own sake, thou dost no longer require thy physical body in its present form. If thine intention were merely to acquire the faculties necessary for life in the supersensible world, thou needest no longer return to the sense-world. But now behold me. See how sublimely I tower above all that thou hast made of thyself thus far. Thou hast attained thy present degree of perfection thanks to the faculties thou wert able to develop in the sense-world as long as thou wert still confined to it. But now a new era is to begin, in which thy liberated powers must be applied to further work in the world of the senses. Hitherto thou hast sought only thine own release, but now, having thyself become free, thou canst go forth as a liberator of thy fellows. Until today thou hast striven as an individual, but now seek to coordinate thyself with the whole, so that thou mayst bring into the supersensible world not thyself alone, but all things else existing in the world of the senses. Thou wilt some day be able to unite with me, but I cannot be blessed so long as others remain unredeemed. As a separate freed being, thou wouldst fain enter at once the kingdom of the supersensible; yet thou wouldst be forced to look down on the still unredeemed beings in the physical world, having sundered thy destiny from theirs, although thou and they are inseparably united. Ye all did perforce descend into the sense-world to gather powers needed for a higher world. To separate thyself from thy fellows would mean to abuse those very powers which thou couldst not have developed save in their company. Thou couldst not have descended had they not done so; and without them the powers needed for supersensible existence would fail thee. Thou must now share with thy fellows the powers which, together with them, thou didst acquire. I shall therefore bar thine entry into the higher regions of the supersensible world so long as thou hast not applied all the powers thou hast acquired to the liberation of thy companions. With the powers already at thy disposal thou mayst sojourn in the lower regions of the supersensible world; but I stand before the portal of the higher regions as the Cherub with the fiery sword before Paradise, and I bar thine entrance as long as powers unused in the sense-world still remain in thee. And if thou dost refuse to apply thy powers in this world, others will come who will not refuse; and a higher supersensible world will receive all the fruits of the sense-world, while thou wilt lose from under thy feet the very ground in which thou wert rooted. The purified world will develop above and beyond thee, and thou shalt be excluded from it. Thus thou wouldst tread the black path, while the others from whom thou didst sever thyself tread the white path.” — Ibid., chapter 11.
“[I]f a man wishes to find the spirit behind and pervading the outer world, he must traverse with full awareness a region of which in normal life he is unconscious; he must traverse consciously the very stream which in everyday life takes consciousness from him. If then he allows himself to be affected by feelings kindled by the cyclic course of Nature herself or by concepts and ideas such as those referred to, if, in short, he achieves real self-development, he gradually becomes capable of fearlessly approaching that spiritual Power who is at first invisible. Just as the Inner [i.e., lesser] Guardian of the Threshold is imperceptible to ordinary consciousness, so too is this second Guardian, the greater guardian of the Threshold, who stands before the spiritual Macrocosm. He becomes more and more perceptible to one who has undergone due preparation and is making his way along the other path into the spiritual Macrocosm. He must fearlessly and without falling into bewilderment pass this spiritual Being who also shows us how insignificant we are and that we must develop new organs if we aspire to penetrate into the Macrocosm. If a man were to approach this Greater Guardian of the Threshold consciously, but still unprepared, he would be filled with fear and despair.
“We have now heard how with his normal consciousness man is enclosed within the frontiers marked by two portals. At the one stands the Lesser Guardian of the Threshold, at the other, the Greater Guardian of the Threshold. The one portal leads into man's inner being, into the spirit of the Microcosm; the other portal leads into the spirit of the Macrocosm. But now we must realise that from this same Macrocosm come the spiritual forces which build up our own being. Whence comes the material for our physical and etheric bodies? All the forces which there converge and are so full of wisdom, are arrayed before us in the Great World when we have passed the Greater Guardian of the Threshold. We are confronted there not by knowledge only. And that is another point of importance. Until now I have been speaking only of knowledge that can be acquired by man but it does not yet become insight into the actual workings and forces of the Macrocosm. The body cannot be built out of data of knowledge; it must be built out of forces. Once past the mysterious Being who is the Greater Guardian of the Threshold, we come into a world of unknown workings and forces. To begin with, man knows nothing of this realm because the veil of the sense-world spreads in front. But these forces stream into us, have built up our physical and etheric bodies. This whole interplay, the interactions between the Great World and the Little World, between what is within and what is without, concealed by the veil of the sense-world — all this is embraced within the bewildering labyrinth. It is life itself, in full reality, into which we enter and have then to describe.” — Rudolf Steiner, MACROCOSM AND MICROCOSM (Rudolf Steiner Press, 1968), lecture 3, GA 119.
“The ant stands at quite a different stage from the beaver, and much further from us, because it already separated off at a much earlier planetary condition of the earth. In its one-sided development it has advanced much further than man. Man thinks, feels, wills, in fixed connection. If I see something which pleases me I grasp at it; the idea evokes the will. Without this interaction man would be very insecure. With the Chela [i.e., student of the mysteries], will, idea, and feeling are torn asunder, and must be quite separate. For general humanity that will first be attained at the Jupiter stage of the earth. But before he experiences this, the Guardian of the Threshold meets him, and gives him clarity about the whole of his previous life.” — Rudolf Steiner, “The Animal Soul” (transcript, Rudolf Steiner Archive), a lecture, GA 97.
“If the student of the spiritual has experienced intuition, he not only knows the images of the psycho-spiritual world, he cannot merely read their connections in the 'occult script,' but he attains to knowledge of the spiritual beings themselves through whose co-operation the world, to which the human being belongs, comes into existence. In this way he learns to know himself in the form he possesses as a spiritual being in the world of soul and spirit. He has struggled through to a perception of his higher ego, and he has become aware of how he has to continue his efforts in order to control his Doppelganger, the 'guardian of the threshold.' He has, however, also encountered the 'greater guardian of the threshold,' who stands before him as an ever present exhorter to further effort. This 'greater guardian' becomes the ideal toward which he strives. If this feeling emerges in the student of the spiritual, he has then acquired the possibility of recognizing who it is that stands there before him as the 'greater guardian of the threshold.' To the perception of the student of the spiritual this guardian now transforms himself into the form of the Christ, whose Being and participation in Earth evolution has been made clear in the previous chapters of this book. The student is now initiated into the exalted mystery that is linked with the name of the Christ. The Christ shows Himself to the student as the 'great ideal of man on earth.' — If thus through intuition the Christ is recognized in the spiritual world, what occurred historically on earth in the fourth post-Atlantean evolutionary epoch — the Greco-Latin epoch — also becomes comprehensible. The way in which, at that time, the exalted Sun Being, the Christ, has intervened in the Earth evolution and how he continues to work within this evolution becomes the personally experienced knowledge of the student of the spiritual. It is thus a revelation of the meaning and significance of Earth evolution that the student receives through intuition. The way to knowledge of the supersensible worlds, which is described here, is one that every human being can follow, no matter what the situation in which he may find himself within the present-day conditions of life. When describing such a path we must consider that the goal of knowledge and truth is the same in all ages of Earth evolution, but that the starting points of man have been different in different ages. If the human being wishes to tread the path to the spiritual world he cannot at present begin at the same starting point as, for example, the would-be initiate of ancient Egypt. Therefore, the exercises that were imposed upon the student of the spiritual of ancient Egypt cannot be carried out by the modern man without modification. Since that time, human souls have passed through various incarnations, and this advance from incarnation to incarnation is not without meaning and significance. The faculties and qualities of souls alter from incarnation to incarnation. Whoever considers human historical life, be it only superficially, is able to notice that since the twelfth and thirteenth centuries A.D. all life-conditions have changed when compared with previous centuries; that opinions, feelings, and also abilities of human beings have become different from what they were previously. The path to higher knowledge described here is eminently fit for souls who incarnate in the immediate present. It is one that places the point of departure for spiritual development just where the human being now stands in any situation presented by modern life. — Progressive evolution leads mankind in regard to the path to higher knowledge from period to period to ever changing forms, just as outer life changes its forms, and at all times a perfect harmony must prevail between outer life and initiation.” — Rudolf Steiner, AN OUTLINE OF OCCULT SCIENCE (Anthroposophic Press, 1972), chapter 5, part 10.
— Compiled by Roger Rawlings
The sword-wielding title character of Steiner's mystery play
THE GUARDIAN OF THE THRESHOLD
[R. R., 2010, based on image in THE GOETHEANUM
(Philosophical-Anthroposophical Press, 1961), p. 21.
 ZANONI, by Edward Bulwer-Lytton. “Central to the spiritual work on inner development is what Rudolf Steiner calls (following Bulwer Lytton, who introduced the term in his Rosicrucian novel ZANONI)....” — Christopher Bamford, introduction to START NOW! (Rudolf Steiner Press, 2007), a collection of Steiner's teachings, p. 243.
 “Exercises like this [i.e., spiritual exercises prescribed by Steiner] are the only way for students of the spirit to acquire the mental tranquillity that is needed to prevent the soul from leading a second, unhealthy life, like a shadowy double, alongside the higher I when this I is born and especially when it begins to be active." — AN OUTLINE OF ESOTERIC SCIENCE, p. 314. Steiner also described the human double as a demon that rides into earthly life alongside the human soul. [See “Double Trouble”.]