How Should We Understand 2 Corinthians 5:1-5?

A gentleman once wrote concerning 2 Cor 5:1-5:

"This seems to me to be indicating that Paul's mortal body would not be abandoned, but rather improved. That he [sic] "house" is referring to enhancement to his mortal condition which *descends* from God."

MY RESPONSE to Him:

Notice that Paul actually indicates that his earthly tent WILL be dissolved. The NASB rightly translates this verse as follows:

"For we know that if the earthly tent which is our house is torn down, we have a building from God, a house not made with hands,
eternal in the heavens."

Compare this thought with 2 Cor 5:4-5 (NASB)

4 For indeed while we are in this tent, we groan, being burdened, because we do not want to be unclothed but to be clothed, so that what is mortal will be swallowed up by life.

5 Now He who prepared us for this very purpose is God, who gave to us the Spirit as a pledge.

So we are not simply talking about "improving" a mortal body here. The apostle suggests that his earthly tent will undergo dissolution
and it will be replaced by a sturdy house, "eternal in the heavens." Additionally the verse says nothing about a body "descending" from God, but it simply shows that God is the source of the new body:

"Thus, the heavenly dwelling of 2 Cor 5:1, no less than the heavenly commonwealth of Phil 3:19, would be an image for that new age. Not
even death, the final proof of mortality, need cause the apostles to shrink back (4:16a), for they, like all believers, know that their
true home is in heaven" (Furnish, VP. II Corinthians; translated with introduction, notes and commentary. Garden City, N.Y.: Doubleday,
1984).