Gordon Fee argues against Torah Observance
"...the ultimate contrast in Galatians is not between "works" and "faith", but between life under Torah and life by the Spirit. Life under Torah means to come under the very curse from which Christ has set us free; moreover life under Torah does not lead to righteousness, either in terms of relationship with God or in terms of godly behaviour. Only the Spirit, who appropriates the righteousness secured through Christ's death and resurrection, can bring life and effect righteousness of the real kind. So having begun by the Spirit, the Galatians are urged to finish by the Spirit. And this, not only because here alone is the way of life in Christ, but also because here alone is God's own antidote to the life of the flesh. Christ's death provided both freedom from Torah observance and crucifixion with regard to the former way of life; the Spirit appropriates this freedom in such a way that the believer neither lives under the slavery of the law nor makes provision for the indulgence of the flesh. But to "finish" by ten Spirit means to walk by the Spirit; it means, in the final words of the argument, to sow to the Spirit by doing (lit. "working"!) what is good to all people, especially those of one's own family in Christ."
-- Fee, Gordon (2007). Pentecostal Commentary on Galatians. Pages 242-243.