In a spiritual brotherhood, people are the elements that unite in order to realize the highest ideal: the kingdom of God on earth
"Concentration is an accumulation of forces and materials within a given space, with regard to a certain work, a future creation, and it manifests first of all as a limitation. Even God limited himself in order to create the world, which is expressed symbolically in this verse from the book of Proverbs: ‘…when he drew a circle on the face of the deep...’ Concentration is necessary for formation; we cannot create anything without first gathering elements and uniting them. At a higher level, we can say that a brotherhood between men and women can also be called a form of concentration. It actually represents the highest expression of spirituality, for here the elements are souls which come together around an idea and collaborate in its realization. In a spiritual brotherhood, people are the elements that unite in order to realize the highest ideal: the kingdom of God on earth."