Rudolf Steiner: "Suffering, once overcome, becomes an increase in energy which we put to use in a new life, and the more we work, the more we overcome suffering, the stronger this energy will be. In a higher sense we can only suffer in good fortune [Im Glück kann man im höheren Sinn nur leiden]: it is a fulfillment from previous lives. In pain we can develop forces, and these forces, developed by the overcoming of pain, represent growth for future life. And we step through the portal of death reassured when we know that death has to be brought into life so that life can rise from stage to stage. It therefore seems justified when it is said that spiritual science in this sense is not just a theory but is sap and energy for life, where what flows directly into our whole soul-existence makes it healthy, vigorous, and strong. Spiritual science is what bears testimony to the words that must live in the soul of every spiritual researcher and indeed in every individual who has an inkling of the spiritual world, as words of truth, as words of guidance for their ascending, healthy, and vigorous life — [a life] that, in the overcoming of pain, sees an increase in forces. It shows the truth of these words:
Riddle upon riddle occupies space,
Riddle upon riddle flows in time;
The solution comes only from the spirit
That grasps itself
Beyond the limits of space
And beyond the flow of time.
Source: Vienna, March 19, 1910. Macrocosm and Microcosm, 2021 ed., p. 24