Deuteronomy 6:25

And it will be righteousness for us, if we are careful to do all this commandment before the LORD our God, as he has commanded us.’ (Deuteronomy 6:25 ESV)

Someone asked my thoughts on Deut 6:25 and I thought it would be worth sharing this brief response. Obedience to the letter is not a perspective shared by all who hold to 1689 Federalism (for example, Owen explicitly mentions disagreeing with it), but I think it is generally correct.

Keeping in mind the distinction between the law as covenant for national Israel for life in the land (which required outward conformity to the letter of the law) and the law as covenant for Adam and his offspring for eternal life (which required inward, perfect obedience to the spirit of the law), I believe Deut 6:25 in its immediate context refers to the former, though as the whole covenant order of Israel speaks typologically, it has reference ultimately to each individual’s inability to obtain true everlasting righteousness by the law.

Cf. Deut 6:25 with 1 Sam 11:13; Phil 3:6; Matt 19:16-22

John Erskine (1765, Scottish Presbyterian) notes:

He who yielded an external obedience to the law of Moses, was termed righteous, and had a claim in virtue of this his obedience to the land of Canaan, so that doing these things he lived by them (s). Hence, says Moses (t), “It shall be our righteousness, if we observe to do all thefe commandments,” i. e. it shall be the cause and matter of our justification, it shall found our title to covenant blessings. But to Spiritual and heavenly blessings, we are entitled only by the obedience of the son of God, not by our own. The Israelites were put upon obedience as that which would found their claim to the blessings of the Sinai covenant. But they were never put upon seeking eternal life by a covenant of works. It is on this account, that the Mosaic precepts are termed, Heb. ix. 10, carnal ordinances, or, as it might be rendered, righteousnesses of the flesh, because by them men obtained a legal outward righteousness(s) Lev. xviii. 5. Deut. v. 33. (t) Deut. vi.25

…Deut 26:12-15

Would God have directed them, think you, to glory in their observance of that law, if, in fact, the sincerest among them had not obferved it. Yet doubtless that was the case, if its demands were the same as those of the law of nature. But indeed, the things mentioned in that form of glorying were only external performances, and one may see, with half an eye, many might truly boast they had done them all, who were strangers not with-standing to charity, flowing from a pure heart, a good conscience, and faith unfeigned. Job, who probably reprefents the Jews after their return from the Babylonifh captivity, was perfect and upright {v). Zacharias and Elizabeth were both righteous before God, walking in all the commandments and ordinances of the Lord blameless(w). The young man, who came to Jesus, enquiring what he should do to inherit eternal life, professed that he had kept the commandments from his youth up, and our Lord does not charge him with falsehood in that profession (x). Paul was, touching the righteoufnefs which was of the law, blamelefs (y). Yet Job curses the day in which he was born (z) Zacharias is guilty of unbelief {a) ; the young man, in the gospel loves this world better than Christ (b) ; and Paul himself groans to be delivered from a body of sin and death (c), These seeming contradictions will vanish, if we take notice, that all of these though chargeable with manifold breaches of the law of nature, had kept the letter of the Mosaic law, and thus were entitled to the earthly happiness promised to its observers.

(v) Job i. i» xix. 20. (a) Luke i. ao. vii. 24. Luke i. 6. (x) Matth. (y) Phil. iii. 6. (z) Job iii. i, 3. (Jb) Mat. xix, 22, 23. (c) Rom.