30:4.18

4. Morontia Progressors. From the mansion worlds on up through the spheres of the system, constellation, and the universe, mortals are classed as morontia progressors; they are traversing the transition spheres of mortal ascension. As the ascending mortals progress from the lower to the higher of the morontia worlds, they serve on countless assignments in association with their teachers and in company with their more advanced and senior brethren.