The Greek is more emphatic than the simple future of the verb in English expresses it. For those who live after the flesh death is inevitable. Compare ch. 6:21.

That is, put to death. The tense is present, indicating a continuous process of putting to death.

 Or, “the practices of the body.” Paul is referring to the actions of the body considered in their moral tendency, which in this case are toward evil. In this verse Paul seems to be restating his whole argument developed in the two preceding chapters, that living carnally means death, but crucifying the flesh means life. See especially chs. 6:6; 8:6. The Christian must not yield to bodily impulses and appetites, except to the extent that they conform to the law of God. His eating and drinking and everything that he does must be performed with a regard for the glory of God (1 Cor. 10:31).

 This is the simple future of the verb and thus differs somewhat from the form of the expression “ye shall die” (see above on this phrase). The distinction may reflect the fact that, whereas death is the inevitable consequence of a life after the flesh, yet eternal life is not exactly the inevitable consequence of mortifying the deeds of the body. It is rather the gift of God through Christ (see on ch. 6:23).

 Whatever professions of spiritual life we may make, it remains forever true that, if we live according to the flesh, we shall die (see Gal. 6:7, 8; Eph. 5:5, 6; Phil. 3:18, 19; 1 John 3:7, 8). Either our sins must die or we must. If they are allowed to live, we shall die. If they are put to death, we shall be saved. No man can be saved in his sins.