Galater 5:17

For--the reason why walking by the Spirit will exclude fulfilling the lusts of the flesh, namely, their mutual contrariety. the Spirit--not "lusteth," but "tendeth (or some such word is to be supplied) against the flesh." so that ye cannot do the things that ye would--The Spirit strives against the flesh and its evil influence; the flesh against the Spirit and His good influence, so that neither the one nor the other can be fully carried out into action. "But" (Gal 5:18) where "the Spirit" prevails, the issue of the struggle no longer continues doubtful (Rom 7:15-20) [BENGEL]. The Greek is, "that ye may not do the things that ye would." "The flesh and Spirit are contrary one to the other," so that you must distinguish what proceeds from the Spirit, and what from the flesh; and you must not fulfil what you desire according to the carnal self, but what the Spirit within you desires [NEANDER]. But the antithesis of Gal 5:18 ("But," &c.), where the conflict is decided, shows, I think, that here Gal 5:17 contemplates the inability both for fully accomplishing the good we "would," owing to the opposition of the flesh, and for doing the evil our flesh would desire, owing to the opposition of the Spirit in the awakened man (such as the Galatians are assumed to be), until we yield ourselves wholly by the Spirit to "walk by the Spirit" (Gal 5:16, Gal 5:18).

In this chapter the apostle comes to make application of his foregoing discourse. He begins it with a general caution, or exhortation (Gal 5:1), which he afterwards enforces by several considerations (Gal 5:2-12). He then presses them to serious practical godliness, which would be the best antidote against the snares of their false teachers; particularly, I. That they should not strive with one another (Gal 5:13-15). II. That they would strive against sin, where he shows, 1. That there is in every one a struggle between flesh and spirit (Gal 5:17). 2. That it is our duty and interest, in this struggle, to side with the better part (Gal 5:16, Gal 5:18). 3. He specifies the works of the flesh, which must be watched against and mortified, and the fruits of the Spirit, which must be brought forth and cherished, and shows of what importance it is that they be so (Gal 5:19-24). And then concludes the chapter with a caution against pride and envy.

5:17 We cannot simply decide to keep the law and not sin: A war rages between God’s Spirit and our sinful nature (see Rom 7:14-25; 1 Pet 2:11; cp. Gen 4:7). The answer is not human effort at law-keeping, but living by God’s Spirit. When we are resurrected, we will finally be freed from sin (see Rom 8:18-25).