There is a general agreement, East and West, that life in a body provides uniquely good opportunities for achieving salvation or deliverance. Catholic and Mahayana Buddhist doctrine is alike in insisting that the soul in its disembodied state after death cannot acquire merit, but merely suffers in purgatory the consequences of its past acts.
But whereas Catholic orthodoxy declares that there is no possibility of progress in the next world, and that the degree of the soul's beatitude is determined solely by what it has done and thought in its earthly life, the eschatologists of the Orient affirm that there are certain posthumous conditions in which meritorious souls are capable of advancing from a heaven of happy personal survival to genuine immortality in union with the timeless, eternal Godhead.
And, of course, there is also the possibility (indeed, for most individuals, the necessity) of returning to some form of embodied life, in which the advance towards complete beatification, or deliverance through enlightenment, can be continued. Meanwhile, the fact that one has been born in a human body is one of the things for which, says Shankara, one should daily give thanks to God.
~ Aldous Huxley, The Perennial Philosophy