There can be no doubt that in this whole context the Apostle has in mind the great passage in Isaiah lix. where the prophet, in a figure of extreme boldness, describes the Lord as arming Himself to deliver the oppressed faithful, and coming as a Redeemer to Zion. In that passage the Lord puts on righteousness as a breastplate--that is to say, God, in His manifestation of Himself for the deliverance of His people, comes forth as if arrayed in the glittering armour of righteousness. Paul does not shrink from applying the same metaphor to those who are to be 'imitators of God as beloved children,' and from urging upon them that, in their humble degree and lowly measure, they too are to be clothed in the bright armour of moral rectitude. This righteousness is manifested in character and in conduct, and as the breastplate guards the vital organs from assault, it will keep the heart unwounded. We must note that Paul here gathers up the whole sum of Christian character and conduct into one word. All can be expressed, however diversified may be the manifestations, by the one sovereign term 'righteousness,' and that is not merely a hasty generalisation, or a too rapid synthesis. As all sin has one root and is genetically one, so all goodness is at bottom one. The germ of sin is living to oneself: the germ of goodness is living to God. Though the degrees of development of either opposite are infinite, and the forms of its expression innumerable, yet the root of each is one. Paul thinks of righteousness as existent before the Christian soldier puts it on. In this thought we are not merely relying on the metaphor of our text, but bringing it into accord with the whole tone of New Testament teaching, which knows of only one way in which any soul that has been living to self, and therefore to sin, can attain to living to God, and therefore can be righteous. We must receive, if we are ever to possess, the righteousness which is of God, and which becomes ours through Jesus Christ. The righteousness which shines as a fair but unattainable vision before sinful men, has a real existence, and may be theirs. It is not to be self-elaborated, but to be received.