The mission of  spiritual knowledge is to permeate, not to escape from material existence

It has only been possible to give a very bare outline of this subject. Abundant literature exists today and is at the disposal of everybody. In one brief lecture I have only been able to indicate certain guiding lines, but what has been said will to some extent show you that anthroposophical knowledge of the super-sensible worlds has not the slightest tendency to be remote from the world, to be unpractical. It does not wish to lead human beings in their egotism into vapid castles in the air; on the contrary, it holds that to alienate a man from the world would be to sin against the Spiritual.

The Spirit is only truly within our grasp when the flow of its power makes us practical and capable human beings.
The Spirit is creative; the mission of the Spirit is to permeate, not to escape from material existence. Anthroposophical knowledge of the super-sensible worlds is therefore at the same time a power in practical life. Hence — as I shall show in other lectures here in Christiania — Anthroposophy strives to enrich the several sciences, the life of art, as well the domains of practical life, with all that knowledge of the reality of higher worlds can add to the things of the material world.

Source: Rudolf Steiner – GA 79 – On the Reality of Higher Worlds – Christiania (Oslo), November 25, 1921

Translation by D. S. Osmond