Adam Clarke on Romans 8:10

And if Christ be in you, etc. - This is the criterion by which you may judge of the state of grace in which ye stand. If Christ dwell in your hearts by faith, the body is dead because of sin, δι' ἁμαρτιαν, in reference to sin; the members of your body no more perform the work of sin than the body of a dead man does the functions of natural life. Or the apostle may mean, that although, because of sin, the life of man is forfeited; and the sentence, dust thou art, and unto dust thou shalt return, must be fulfilled on every human being, until the judgment of the great day; yet, their souls being quickened by the indwelling Spirit of Christ, which enables them to live a life of righteousness, they receive a full assurance that their bodies, which are now condemned to death because of sin, shall be raised again to a life of immortal glory.