As to the soul of man after death

Though death destroy his body, it has no power over his spirit—this is eternal, everlasting, both birthless and deathless.
As to the soul of man after death, it remains in the degree of purity to which it has evolved during life in the physical body, and after it is freed from the body it remains plunged in the ocean of God’s Mercy.
From the moment the soul leaves the body and arrives in the Heavenly World, its evolution is spiritual, and that evolution is: The approaching unto God.
In the physical creation, evolution is from one degree of perfection to another... In this world things live and die, and live again in other forms of life, but in the world of the spirit it is quite otherwise.
The soul does not evolve from degree to degree as a law—it only evolves nearer to God, by the Mercy and Bounty of God.

`Abdu'l-Bahá: Paris Talks. p.67