That is one of the first conditions of our evolution

The two principles of spirit and matter appear to be in conflict, but in reality they work together to serve life. And while the principle of matter develops, day in, day out, expanding its territory in humans, the spirit, which does not remain inactive, attempts to show them that there are also subtler regions to visit, more grandiose tasks to accomplish. Some refuse, stubbornly focusing their efforts on the physical plane. The physical body and material conditions should not be neglected, but we must set ourselves limits, for we are on earth for a short while only. And it is not enough just to know it theoretically. An awareness of the ephemeral nature of all material form, and thus of our physical body, should drive us to seek the spirit, which does away with forms, ceaselessly creating new ones. That is one of the first conditions of our evolution.