To understand the matter of Gan Eden of the earth, where the souls go up to specifically when they are purified: it is known that 4 rivers go out from Gan Eden in a literal sense, that there is a special place on the globe of the physical earth on the equator, 32 degrees distance from Yerushalayim, and there is the dwelling place of the Gan and a river goes out.
The fact that they haven't found it on the face of the earth, and the fiery sword is not seen, is because this Gan has the aspect of Divine spirituality, as is known that the soil of the Gan is also above the spirituality of the four fundemental elements of fire, air, water, and earth which are mixed with good and evil.
But the spirituality of the 4 fundemental elements becomes the soil for this Gan in a way that there is no admixture of evil at all, because this place is separated in spirituality from all admixture of good and evil, like the body of Adam Harishon, which was made from this dust that is in the soil of the Gan, and would make the sun look dark, etc. And so, if he would not have sinned with the tree of knowledge, etc., he would have been at the ultimate level of Divine holiness, except that he sinned with the Tree of Knowledge of Good and Evil and couldn't remain in Gan Eden, as it says "the man was expelled..."
Mitteler Rebbe Maamorim, Vayikra II:703