1 Corinthians 15:44
σπείρεται σῶμα ψυχικόν ἐγείρεται σῶμα πνευματικόν ἔστιν σῶμα ψυχικόν καὶ ἔστιν σῶμα πνευματικόν
σῶμα ψυχικόν (soma psuchikon), literally "body soulish". The Greek word psuchikos is the adjective form of the word psuche ("soul"). It is unfortunate that it has been often translated as "natural" since that has given rise to a great deal of confusion, though one can likely get an idea of what the translators were trying to capture. English doesn't have a word that directly translates psuchikos. Saying this word means "soulish" isn't unique to me, it's the fairly standard way exegetes and biblical scholars attempt to render the more clear meaning of the text--unfortunately "soulish" isn't an actual word in English, it's a made up word to try and bring clarity to what the Greek word means.
σῶμα πνευματικόν (soma pneumatikon), literally "body spiritual".
Paul is not contrasting the physical with the spiritual; he is contrasting the "soulish" with the "spiritual". This isn't the first time Paul uses this contrast, elsewhere he speaks of "soulish" people, contrasting them with "spiritual" people--most translations render it as "natural" or "carnal". But when Paul says that we were formally "soulish" but now we are "spiritual", he is not talking about going from physical to spiritual, but from being a people ruled by our animal lusts and appetites to having received the Holy Spirit. For Paul what makes someone or something "spiritual" is the Holy Spirit. And the same is true here.
The body, presently, is mortal, corruptible (meaning it decays), and we are ruled by our "soul", by our animal appetites, the lusts of the flesh, etc. We are "soulish" creatures, sinful, acting according to our belly, the sort of life we have now is animal life. But Paul looks forward to the resurrection as when the body is raised up and transformed, no longer being subject to the mortality, corruptibility, and futility of sin and death, no longer driven by the baser animal desire--but instead quickened, made alive, by the power of the Holy Spirit.
Elsewhere the Apostle says, "If the Spirit of Him who raised Christ from the dead is also in you, then He who raised Christ from the dead will give life to your mortal bodies." (Romans 8:11).
It is the Spirit who quickens, the Spirit who makes alive. That's why in the Creed we call Him "Life-Giver"
It is precisely our glorification by the power of the Spirit in the resurrection that the Apostle is looking forward to, when we are raised up we are not merely returned to a state of mortal corruption laboring under sin and death again; when we are raised up we are raised up to immortality and incorruption, to the eternal, never-ending life that is to come. It is an entirely new way to be alive, it's the way Jesus is alive, fully alive in the body, but without decay; for Christ conquered death, and at the resurrection death shall be fully destroyed, since death shall be swallowed up in victory: "Where O Death is your sting? Where O Death is your victory?" At the resurrection Christ will transform our lowly bodies of humiliation to be like His glorified body (Philippians 3:21).
-CryptoLutheran