But this is what I mean by allegorising. You assert that “creation” = Israel, “vanity” = the Law, the “old man” = the old covenant, the “new man” = the new covenant. But none of this is evident in the texts. It sort of works as an allegory, but there is no way of determining that this is how Paul meant it to be understood.
Paul doesn’t say that the “creation” is renewed in the “firstfruits of the Spirit”. He says that creation hopes eventually to attain the same freedom from corruption that the “sons of God” will have when they are revealed to the world.
The possessive pronoun “our” makes it very unlikely that the singular body (sōmatos) in Romans 8:23 is the corporate body of the firstfruits. We would expect “the redemption of the body”. The same construction is found in 2 Corinthians 4:10-11 and is presumably idiomatic:
…always carrying in the body the death of Jesus, so that the life of Jesus may also be manifested in our body (en tōi sōmati hēmōn). For we who live are always being given over to death for Jesus’ sake, so that the life of Jesus also may be manifested in our mortal flesh.
In this case, the parallel with “in our mortal flesh” (en tēi thnētēi sarki hēmōn) makes it clear that the reference is to the personal body.
When Paul speaks about putting off the “old person” and putting on the new (Eph. 4:22; Col. 3:9), he is primarily addressing Gentile believers, who cannot be said to have put off the old covenant.