The Christian is characterized, not by flesh (that is, human nature fallen, estranged from God), but the Spirit.
The Holy Spirit is an indwelling Person, who acts in and with the believer.
All were alike in the same state, "in flesh," as born of Adam, but those according to the Spirit mind the things of the Spirit, things which eye has not seen nor ear heard, neither has it entered the heart of man to consider, things which God has prepared for those that love Him. [8]