Neither can environmental limitations, even on an isolated world, thwart the personal attainment of the individual mortal; Jesus of Nazareth, as a man among men, personally achieved the status of light and life over nineteen hundred years ago on Urantia.  Such divinely watered souls are all but independent of material environment as regards the joys of living and the satisfactions of earthly existence.  Life Carriers manipulated environment to eliminate inferior prehuman strains.  There can be no handicap of human heredity or deprivation of mortal environment which the morontia career will not fully compensate and wholly remove.  Religious experience is markedly influenced by physical health, inherited temperament, and social environment.  Seraphim, Master Physical Controllers, and midwayers manipulate terrestial environment. 
The mortals may differ greatly in innate abilities and intellectual endowment, they may enjoy environments exceptionally favorable to social advancement and moral progress, or they may suffer from the lack of almost every human aid to culture and advancement in the arts of civilization.  But spiritual progress is opened to all regardless of environment.