It’s only right that both body and soul should flourish in the supernatural World to Come, after the Messianic Era, rather than the soul alone. After all, “body and soul accomplish everything together in this world, both right and wrong” Ramchal offers, so it’s only fair that “they be recompensed together” in full.
Understand that the close rapport between body and soul, and what’s sometimes termed their “marriage”, is a very basic Jewish concept. It helps to explain the respect that Halacha accords the body as when it requires us to eat well and fully on the Shabbat, by its not denigrating wealth, and by the fact that celibacy is frowned upon.
(But it’s important to realize that while this holistic approach is seen as self-evident and incontrovertible in our day and age, that wasn’t always so. Many medieval thinkers took great pains to separate body from soul, and saw any effort to suggest that the body would eventually be rewarded as being “too Jewish” and by implication, primitive. While we’re certainly proud to be on the winning side of this argument in our day and age, the controversy only underscores the fact that the truths of Torah have always been out of fashion at one time or another.)
The point remains though that the body must die and molder in the dust, and be separated from the soul for the extent of the Afterlife. And all because of Adam and Eve’s terrible mistake of not heeding G-d’s warning to, “not eat from the Tree of the Knowledge of Good and Evil — for you will surely die on the day that you eat from it” (Genesis 2:17).
In any event, the body is then purified through the process of obliteration, while the soul experiences the Afterlife, termed “The Soul World”, where it awaits the time when it will be joined to the body’s elements once again and be brought back to life with it. And then the two will be granted a place in The World to Come, where, “body and soul together will bask in The Light of Life for eternity” as Ramchal puts it, “and enjoy true goodness in accordance to their deeds in life”.
Ramchal doesn’t touch upon it here (though he cites it elsewhere) but we’re likewise taught that reincarnation plays a role in the Divine merit- system as well. There are a lot of technical details involved, touching upon who’s to be reincarnated and who not, which body will return with which soul when we’re reunited, how many times we’re allowed to come back, why one would have to come back anyway as opposed to experiencing the Afterlife, and more. But at bottom the point is that there are many ways to be readied for the World to Come and to experience it, and that the great preponderance of us is allowed his or her share in it. For we’re assured that “G-d your L-rd is a merciful G-d; He will not abandon or destroy you” (Deuteronomy 4:31), and that “G-d does not take away a life, but He devises means so that His banished ones are never expelled from Him” (2 Samuel 14:14).
Rabbi Yaakov Feldman has translated and commented upon “The Gates of Repentance”, “The Path of the Just”, and “The Duties of the Heart” (Jason Aronson Publishers). His works are available in bookstores and in various locations on the Web.