“The reference is not to two coexisting sides in the constitution of the Saviour, but to two successive stages in his life: there was first a genesthai kata sarka, then a horisthenai kata pneuma. The two prepositional phrases have adverbial force: they describe the mode of the process, yet so as to throw emphasis rather on the result than on the initial act: Christ came into being as to his sarkic existence, and he was introduced by horismos into his pneumatic existence … By the twofold kata the mode of each state of existence is contrasted, by the twofold ek the origin of each. Thus the existence kata sarka originated ‘from the seed of David’, the existence kata pneuma originated ‘out of resurrection from the dead’ … The resurrection is to Paul the beginning of a new status of sonship: hence, as Jesus derived his sonship kata sarka from the seed of David, he can be said to have derived his divine-sonship-in-power from the resurrection … The resurrection is characteristic of the beginning of a new order of things, as sarkic birth is characteristic of an older order of things. What stands before the Apostle’s mind is the contrast between the two aeons … Paul is not thinking of the resurrection of Christ as an event, but of what happened to Christ in its generic qualitative capacity, as an epoch partaking of a strictly eschatological nature. From resurrection-beginnings, from an eschatological genesis dates the pneumatic state of Christ’s glory which is described as a sonship of God en dynamei” (EAPCS, 229-30  = 104-5 ).
Richard B. Gaffin, Jr.:
“A proper interpretation of these verses must appreciate the centrality of the temporal factor minimized by Warfield … The pneuma-sarx antithesis, then, while it has important anthropological implications, is fundamentally a historical contrast. Intrinsic to it is what Warfield dismisses in passing, the capacity for expressing temporal distinction. It is an antithesis between two aeons, one present and one coming, between the old world order which is passing away and the new which remains … The phrase [kata sarka] brings into view not only Christ’s human nature but also and pointedly the order into which the assumption of humanity brought him, the environment with which this humanity is necessarily associated and from which it cannot be abstracted. The full thought of verse 3 is that by incarnation (by being born of the seed of David) the eternal Son of God entered the sphere of sarx, the old aeon, the present evil age … By resurrection the preexistent Son, having become incarnate in the old order …, entered the sphere of the Spirit, the new aeon, the coming age; his personal, incarnate mode of existence is now conformed to the pneumatic world-order entered at the resurrection … Verse 4, then, is of a piece with I Corinthians 15:45 and II Corinthians 3:17” (R&R, 105, 109-10).