38:4.1 The ninth group of seven primary spheres in the Salvington circuit are the worlds of the seraphim. Each of these worlds has six tributary satellites, whereon are the special schools devoted to all phases of seraphic training. While the seraphim have access to all forty-nine worlds comprising this group of Salvington spheres, they exclusively occupy only the first cluster of seven. The remaining six clusters are occupied by the six orders of angelic associates unrevealed on Urantia; each such group maintains headquarters on one of these six primary worlds and carries on specialized activities on the six tributary satellites. Each angelic order has free access to all the worlds of these seven diverse groups.
38:4.2 These headquarters worlds are among the magnificent realms of Nebadon; the seraphic estates are characterized by both beauty and vastness. Here each seraphim has a real home, and "home" means the domicile of two seraphim; they live in pairs.
38:4.3 Though not male and female as are the Material Sons and the mortal races, seraphim are negative and positive. In the majority of assignments it requires two angels to accomplish the task. When they are not encircuited, they can work alone; neither do they require complements of being when stationary. Ordinarily they retain their original complements of being, but not necessarily. Such associations are primarily necessitated by function; they are not characterized by sex emotion, though they are exceedingly personal and truly affectionate.
38:4.4 Besides designated homes, seraphim also have group, company, battalion, and unit headquarters. They forgather for reunions every millennium and are all present in accordance with the time of their creation. If a seraphim bears responsibilities which forbid absence from duty, she alternates attendance with her complement, being relieved by a seraphim of another birth date. Each seraphic partner is thereby present at least every other reunion.