A.T. Robertson Commentary Romans 8:10

"And if Christ is in you, the body is dead because of sin; but the spirit is life because of righteousness." — Romans 8:10 (ASV)

The body is dead (το μεν σωμα νεκρον). Has the seeds of death in it and will die "because of sin."

The spirit is life (το δε πνευμα ζωη). The redeemed human spirit. He uses ζωη (life) instead of ζωσα (living), "God-begotten, God-sustained life" (Denney), if Christ is in you.