Bondmen of Righteousness.
I. St. Paul's manner of thinking is frequently hard to follow. One peculiarity which contributes to make it a difficult exercise to track his reasoning is this: on the threshold of a fresh train of ideas, when the subject which fills his mind has been no more than started, it is not uncommon to find him suddenly break off in order to interject some side thought which has just occurred to him. Of this habit we have an instance before us. The objection springs up suddenly. If a Christian is no longer under the law of Moses, but under the free, that is, the unmerited, favour of God as the source of His salvation, is not this a distinct licence to him to sin? To that recurring difficulty there never has been, nor ever can be, any valid reply save one: this, namely, that the very change which is involved in a man's becoming a believer in God's free grace through Christ renders his continuance in sin a practical impossibility. Christians were slaves to sin once, no doubt; but conversion has broken that service in order that they should enter another. They are now "servants unto righteousness."
II. The expression "enslaved to righteousness" is indeed an unusually strong one, even for St. Paul; so strong that he deems it well to apologise for it (ver. 19). For while the practice of sin is really a moral slavery, as our Lord Himself taught, seeing that it involves the subjugation of what is noblest in a man beneath some base or petty desire of which in his heart he feels ashamed, there is no true bondage in obeying God. On the contrary, the law of righteousness is the law of man's original, proper nature, his native law, so to speak. To follow it is to act freely. Accordingly, when the Apostle spoke about being a slave of righteousness, he employed language which he felt to be harsh, because, in any strict sense of it, both inaccurate and unworthy. Nevertheless, St. Paul endeavours to say what he means in more precise and less metaphorical language. What it amounts to is this. That as a man previous to his conversion to Christ yielded up his faculties to execute lawless desires, and thus did the work of lawlessness as a slave serves his master, so, after conversion has put an end to that, he must, in a similar way, give himself up to perform the lawful or righteous will of God.
J. Oswald Dykes, The Gospel according to St. Paul,p. 182.
References: Romans 6:15-23. Spurgeon, Sermons,vol. xxv., No. 1482; Clergyman's Magazine,vol. i., p. 18; H. J. Wilmot Buxton, The Lifeof Duty,vol. ii., p. 61; Homilist,new series, vol. iv., p. 653; Church of England Pulpit,vol. xxi., p. 125; R. Molyneux, Ibid.,vol. v., p. 189. Romans 6:16-19. E. de Pressensé, Christian World Pulpit,vol. xvi., p. 93.Romans 6:17. Bishop Westcott, The Historic Faith,p. 17.