By ‘many dwelling-places’ (John 14:2) the Savior meant the differing stages of spiritual ascent and states of development in the other world; for although the kingdom of heaven is one, there are many different levels within it. That is to say, there is place for both heavenly and earthy men (cf. 1 Corinthians 15:48) according to their virtue, their knowledge and the degree of deification that they have attained. ‘For there is one glory of the sun, and another glory of the moon, and another glory of the stars, for one star differs from another star in glory’ (1 Corinthians 15:41); and yet all of them shine in a single diving firmament.
~St Gregory of Sinai
Prayerful Life 