From the scientific standpoint, spirit and matter are quite different from each other, but according to the philosophical point of view they are one.
Spirit and matter are different, just as water is different from snow; yet again they are not different, for snow is nothing other than water. When spiritual vibrations become more dense they turn into matter, and when material vibrations become fine they develop into spirit.
For a Sufi at the beginning of his training the spiritual life is desirable, but after mastering it, material and spiritual lives become the same to him, and he is master of both.
Hazrat Inayat Khan A Sufi Message of Spiritual Liberty