We are only separated from the so-called dead through the fact that we are not in a position to perceive with our ordinary consciousness how the forces of the dead, the life of the dead, the actions of the dead, play into our own life. These forces, these actions of the dead, continually permeate the life of our feeling and the life of our will. Therefore we can live with the dead. And it is indeed important to realize at the present time that the task of Anthroposophy is to develop this consciousness — that we are in touch with the souls of the dead.
The earth will not continue to evolve in the direction of the welfare of humanity unless humanity develops this living feeling of being together with the dead. For the life of the dead plays into the life of the so-called living in many ways.
Source: Rudolf Steiner – GA 179 – Historical Necessity and Freewill: Lecture 3: Our Life with the Dead – Dornach, December 10, 1917