The translation of the last clause of this verse, as may be seen from better translations, is altogether faulty. Taking it as it stands, it would teach that both the Spirit and the flesh are equally impotent, or rather that the result for the believer of their mutual antagonism is that he cannot do anything, that, whatever his desires, the desires of the new nature, even though indwelt by the Holy Spirit, he is utterly helpless, cannot do the things he would. An examination of the context (v. 17, for example) shows at once that such a thought is wholly alien from the mind of God; and, in fact, the words should be rendered, "that ye should not do those things which ye desire." This at once clears away the difficulty.
The Galatian saints were not walking according to the character of their calling. Losing the sense of grace, they had put themselves back, through the influence of Judaizing teachers, under law; and the consequence was, that the flesh assumed its old dominant place in their lives. (v. 15.) The only remedy for this, as the Apostle points out, was to "walk in the Spirit." (Compare Rom. 8:1313For if ye live after the flesh, ye shall die: but if ye through the Spirit do mortify the deeds of the body, ye shall live. (Romans 8:13).)
Thereupon he takes occasion to bring before them the abiding character of the flesh, and its irreconcilable contrariety with the Spirit. "The flesh lusteth against the Spirit, and the Spirit against the flesh: and these are contrary the one to the other." The two are, and must ever be, opposed. The flesh will always be evil, and cannot be ameliorated, improved, or changed; and the Spirit, blessed be God, is holy; and it is impossible therefore that the two can be in agreement. The flesh "lusteth" against the Spirit, ever antagonizing, and ever seeking, in opposition to the Spirit, to gratify its own inclinations. The Spirit, on the other hand, is ever in opposition to the flesh, and seeks to repress its activities, and thus to lead the believer according to God.
The question then is, To which shall the believer yield? If by grace he walks in the power of the Spirit, he will not fulfill the lusts of the flesh (v. 16); but if, on the other hand, he surrenders himself to the dominion of the flesh, there is then, as verses 19-21 indicate, no sin, however abominable, into which he may not fall. Give the Spirit His place in our souls, He will produce the beauteous fruit mentioned in verses 22 and 23. But then, as the Apostle warns these saints, it is a characteristic of those "that are Christ's," that they "have crucified the flesh with the affections and lusts." If, therefore, any were allowing the sway of the flesh, let them take heed lest, after all, they had but deceived themselves with a vain profession, and did not really belong to Christ. If we live in the Spirit, let it be seen—for this is the force of the exhortation—by our also walking in the Spirit.