Meditation is for the soul what breathing is for the body.

Ex Deo Nascimur       In Christo Morimur     Per Spiritum Sanctum Reviviscimus

Rudolf Steiner: 

People approach esoteric exercises quite thoughtlessly. Many begin to do them but don't continue out of laziness, half-heartedness, etc. But the meditations are for the soul what breathing is for the physical body. If we gave up breathing, Ahriman, as Lord of Death, would intervene immediately. The soul must come to the point of not having to struggle or force itself to do the meditations; to the point where it does not want to live without them anymore. The meditations must become for the soul what breathing is for the body.


Source: Notes written from memory by a participant in an Esoteric Lesson given by Rudolf Steiner in Munich on September 4, 1913. In Esoteric Lessons, p. 143.