in the flesh = in flesh. No art. or preposition. Dative case.
quickened. See Rom_4:17.
by the Spirit = in spirit. No preposition. (Dative case), and though the Authorized Version has the art. it is rejected by all the texts. App-101. The reference is to the resurrection body, and the contrast is between His condition when He was put to death and when He rose from the dead.