Refining the Body to Surpass Adam Harishon

As our sages say, there is no difference between this world and the days of Moshiach except servitude to the nations. The service will only be in a spiritual manner, and not like Adam Harishon in Gan Eden to work it, etc. in spirituality itself, but rather [it will be] in real physicality itself...but still there will be death because we didn't yet refine the body to the level of Adam before the sin. But at the revival of the dead, when all the souls which passed away will come and go up higher and higher to their bodies...and the bodies will be pure and holy.

Maamorim Mitteler Rebbe, Vayikra II p. 686