There is nothing more harmful to you than improving only your material, animal side of life. There is nothing more beneficial, both for you and for others, than activity directed to the improvement of your soul.
Of lower states, of acts of routine and sense, we can tell somewhat; but the masterpieces of God, the total growths and universalmovements of the soul, he hideth; they are incalculable. I can know that truth is divine and helpful; but how it shall help me I can have no guess, for so to be is the sole inlet of so to know.
The soul is something which contains the body. The body doesn't contain the soul. The soul, if we put it into modern language, is the entire complex of relationships in whose context this organism exists.
There is no health in those who are displeased by an element in Your creation, just as there was none in me when I was displeased by many things You had made. Because my soul didn't dare to say that my God displeased me, it refused to attribute to You whatever was displeasing.
When an idea is just rising on the horizon, the soul's temperature with respect to it is usually very cold. Only gradually does the idea develop its warmth, and it is hottest (which is to say, exerting its greatest influence) when belief in the idea is already once again in decline.