Sri Aurobindo
Letters of Sri Aurobindo
Volume IV - Part 2
The inner loneliness can only be cured by the inner experience of union with the Divine; no human association can fill the void. In the same way, for the spiritual life the harmony with others 
must be founded not on mental and vital affinities, but on the divine consciousness and the union with the Divine. When one finds the Divine and finds others in the Divine, then the real harmony comes. Meanwhile what there can be is the goodwill and unity founded on the feeling of a common divine goal and the sense of being all children of the Mother. Real harmony can come only on a psychic or a spiritual basis.