Modern man has mainly four bodies:
* Material body
* Etheric Body(Chi,Prana)
* Astral body (Wiki)
* Mental body
* Causal body and spirit( Atman, Purusha, Trikaya ), which are not developed in the current human
After the death the etheric body solves up within a few days and the astral soul looses the rememberance of the past incarnation and awakes in the astral world. The weak astral body of a person who had led a life which was very much bound to the (desires of the) body sinks down to the gray region of the underworld where the forces of the sun are absorbed. Greece mythology said about this region : "Better to be a beggar on earth than a king in the world of the shadows".
There the soul can live some ten years and then it sinks mostly down to the underlying dark region (a region parallel to our planet) and perishes there together with the mental body. If the mental body had degenerated during the past incarnation then the astral soul may eventually return into the animal kingdom.
In the normal astral world the astral body can live up to some centuries und dies and reincarnates if it has survived the dangers of the astral world. The mental body and the higher bodies survive the reinkarnations partially.
After reincarnation begins the reconstruction of the bodies in three phases of about seven years and further phases of design of seven years.
With step 10 of the Universal Path the seeker "spins the wheel" and therefore the soul does not sink down into the dark regions(of samsara).
The spiritual man has developed the higher bodies and can wait with the reincarnation for long ages. Condition is the "Rebirth from water and spirit", the begin of the long path or the end of step 14 of the Universal path(Samadhi).
[One key reference to being "born again" is John 3:5, where Jesus says, "Truly, truly, I say to you, unless one is born of water and the Spirit, he cannot enter the kingdom of God."]
First the true master is liberated from the cycle of rebirth und he may incarnate freewillingly or after order of the divine.
"Who is satisfied with little, him I call rich - Who acts powerful - him I call strong-willed. who has not lost his center - he has continuance - who dies and yet does not perish, holds the key to immortality", Tao Te King.