That the righteousness of the law might be fulfilled in us, who walk not after the flesh, but after the Spirit. Romans 8:4
…Believers are to be justified, not by works of righteousness which they have done, of whatever description, but solely by faith in Jesus Christ, in whom their reconciliation with God is complete. It is this grand truth which, from the beginning of the Epistle, he had been exhibiting, for the conviction and establishment in the faith of those whom he addressed. It is indeed a truth in which Christians need to be fully instructed, which they are all apt to let slip out of their minds, but by which they are saved, if they keep it in memory. There is nothing which so much retards them in their course as their proneness to walk according to the flesh, in seeking to establish their own righteousness; and nothing more powerfully tends, when giving way to it in any degree, to bring them into bondage, to lead them to serve in the oldness of the letter, and not in newness of spirit, and to mar their joy and peace in believing.