Unfortunately many people in our modern materialistic age find it very difficult to feel what I might call the holiness of sleep. […] It is indeed a curious phenomenon of man’s intelligence today that he is entirely devoid of respect for the holiness of sleep. We need only consider how many people go to sleep without developing the realisation — which indeed can never become a living thing in a materialistic mind — that sleep unites us with the Spiritual world, that sleep sends us across into the Spiritual world.
(These things are not mentioned by way of blame, nor intended to drive people to asceticism: we must live with the world, but we must at the same time have our eyes open, for only thus can we wrench our bodily nature away from the lower and lift it higher.)
People should at least become gradually able to develop a feeling which can be expressed somewhat as follows: ‘I am going to sleep; until I wake, my soul will be in the Spiritual world. There it will meet with the guiding-power of my earth-life, who lives in the Spiritual world, and who soars round and surrounds my head. My soul will have the meeting with my genius (old term for angel or guardian angel). The wings of my genius will come in contact with my soul.’
Source: Rudolf Steiner – GA 175 – Cosmic and Human Metamorphoses – LECTURE 3: THE HUMAN SOUL AND THE UNIVERSE (Part 1) – Berlin, 20th February 1917
Translated by Harry Collison