The strongest impulses producing this change (of traits of character, of temperament, and so forth R.v.D.) in ordinary life are the religious ones. When the I allows the impulses that flow from religion to act upon it again and again, they form within it a power that works right into the ether body and transforms it in much the same way that lesser life-impulses cause a transformation of the astral body.
These lesser impulses of life, which come to man through study, contemplation, ennobling of the feelings, and so forth, are subject to the manifold changes of existence; religious experiences, however, imprint upon all thinking, feeling, and willing a uniform character. They shed, as it were, a common, uniform light over the entire soul-life. A man thinks and feels this way today, tomorrow differently. The most varied causes bring this about. But if a person through his religious feelings, whatever they may be, divines something that persists throughout all changes, he will relate his current soul experiences of thinking and feeling to that fundamental feeling just as he does with his soul experiences of tomorrow. Religious creed, therefore, has a far-reaching effect upon the whole soul-life; its influence becomes ever stronger in the course of time, because it works by means of constant repetition. It therefore acquires the power of working upon the ether body.
The influence of true art has a similar effect upon the human being. If, through outer form, through color and tone of a work of art, he penetrates to its spiritual basis with thought and feeling, then the impulses that the I thus receives work down even into the ether body. If we think this thought through to the end we can estimate what a tremendous significance art has for all human evolution. We have referred here only to a few instances that give to the I the impulse to act upon the ether body. There are many similar influences in human life that are not so apparent to the observing eye as those that have been mentioned.
Source: Rudolf Steiner – GA 13 – An Outline of Occult Science: II: THE ESSENTIAL NATURE OF MANKIND
Translated by Maud and Henry B. Monges and revised for this edition by Lisa D. Monges