John 14

 In his final training to His disciples before his death, the Savior taught - 

"In my Father’s house are many mansions: if it were not so, I would have told you. I go to prepare a place for you."  (John 14:2)

The Prophet Joseph Smith explained - 

"...it should be, “In my Father’s kingdom are many kingdoms.” Also, “There are mansions for those who obey a celestial law, and there are other mansions for those who come short” (Teachings of the Prophet Joseph Smith, p. 366).

Of many of those other kingdoms or mansions, they  -

"...may enter into the other, but that is the end of his kingdom; he cannot have an increase."  (Doctrine and Covenants 131:4)

Those who qualify for exaltation are they who will have an increase in there kingdom or mansion.