Culture and civilisation are nothing more than work on matter. Human beings will always have work to do with it and on it, but this work of creation is not to be limited to the physical matter outside of them.
Their instincts, desires, feelings and thoughts are also matter they must aim to work on to purify and ennoble it.
Spiritual work is therefore also work on matter. When humans learn to use all the powers of the spirit to work on the matter within them, everything they will then realize on the outside will be marked with the seal of the spirit, with its light, its love and its power.