P541:4, 48:1.1 The morontia realms are the local universe liaison spheres between the material and spiritual levels of creature existence. This morontia life has been known on Urantia since the early days of the Planetary Prince. From time to time this transition state has been taught to mortals, and the concept, in distorted form, has found a place in present-day religions.
P541:5, 48:1.2 The morontia spheres are the transition phases of mortal ascension through the progression worlds of the local universe. Only the seven worlds surrounding the finaliters' sphere of the local systems are called mansion worlds, but all fifty-six of the system transition abodes, in common with the higher spheres around the constellations and the universe headquarters, are called morontia worlds. These creations partake of the physical beauty and the morontia grandeur of the local universe headquarters spheres.
P541:6, 48:1.3 All of these worlds are architectural spheres, and they have just double the number of elements of the evolved planets. Such made-to-order worlds not only abound in the heavy metals and crystals, having one hundred physical elements, but likewise have exactly one hundred forms of a unique energy organization called morontia material. The Master Physical Controllers and the Morontia Power Supervisors are able so to modify the revolutions of the primary units of matter and at the same time so to transform these associations of energy as to create this new substance.
P542:1, 48:1.4 The early morontia life in the local systems is very much like that of your present material world, becoming less physical and more truly morontial on the constellation study worlds. And as you advance to the Salvington spheres, you increasingly attain spiritual levels.
P542:2, 48:1.5 The Morontia Power Supervisors are able to effect a union of material and of spiritual energies, thereby organizing a morontia form of materialization which is receptive to the superimposition of a controlling spirit. When you traverse the morontia life of Nebadon, these same patient and skillful Morontia Power Supervisors will successively provide you with 570 morontia bodies, each one a phase of your progressive transformation. From the time of leaving the material worlds until you are constituted a first-stage spirit on Salvington, you will undergo just 570 separate and ascending morontia changes. Eight of these occur in the system, seventy-one in the constellation, and 491 during the sojourn on the spheres of Salvington.
P542:3, 48:1.6 In the days of the mortal flesh the divine spirit indwells you, almost as a thing apart -- in reality an invasion of man by the bestowed spirit of the Universal Father. But in the morontia life the spirit will become a real part of your personality, and as you successively pass through the 570 progressive transformations, you ascend from the material to the spiritual estate of creature life.
P542:4, 48:1.7 Paul learned of the existence of the morontia worlds and of the reality of morontia materials, for he wrote, "They have in heaven a better and more enduring substance." And these morontia materials are real, literal, even as in "the city which has foundations, whose builder and maker is God." And each of these marvelous spheres is "a better country, that is, a heavenly one."