It is just as necessary for a human being to have knowledge, feeling and perceptiveness of the life between death and the new birth as of earthly life itself. For when he enters earthly life at birth, the confidence, strength and hopefulness connected with that life depend upon what forces he brings with him from the life between the last death and the present birth.
But again, the forces we are able to acquire during that life depend upon our conduct in the earlier incarnation, upon our moral and religious disposition or the quality of our attitude of soul. We must realise that whether the future evolution of the human race will be furthered or impeded depends upon our active and creative co-operation with the super-sensible world in which we live between death and the new birth.
Source: Rudolf Steiner – GA 141 – Between Death and Rebirth – Lecture 2 – Berlin, 20th November 1912