30 What shall we say, then? That Gentiles who did not pursue righteousness have attained it, that is, a righteousness that is by faith; 31 but that Israel who pursued a law that would lead to righteousness  did not succeed in reaching that law. 32 Why? Because they did not pursue it by faith, but as if it were based on works. They have stumbled over the stumbling stone, 33 as it is written, “Behold, I am laying in Zion a stone of stumbling, and a rock of offense; and whoever believes in him will not be put to shame.”
(Romans 9:30-33 (ESV)
10:1 Brothers,  my heart's desire and prayer to God for them is that they may be saved. 2 For I bear them witness that they have a zeal for God, but not according to knowledge. 3 For, being ignorant of the righteousness of God, and seeking to establish their own, they did not submit to God's righteousness.
(Romans 10:1-3 (ESV)
“That Gentiles who did not pursue righteousness have attained it, that is, a righteousness by faith.”
I’m following the lead of Bo Giertz here. He treats Romans 9:30-10:3 as one section in his commentary. He also shows just how dangerous the idea of works righteousness is. Slowly I translate these commentaries bit by bit, mostly in half hazard fashion as I’m working on this blog, and other bible studies and sermon prep. The wonderful thing about them is that they are much more than commentaries, they are like little devotions or sermons. In this manner they richly reflect the tradition of Luther in his commentaries. And in my opinion, this makes them much better than many of the dry and tedious volumes pecking at syntax and parsing the prose. Bo actually lets the text speak. I’ll admit, there are times when I look at my translation schedule for the week and cringe under the weight of self-appointed deadlines. But when I’m in the thick of translating and reading what he writes I find myself refreshed by the gospel every time. I can’t wait to make these available to the English speaking public. Enough of that.
Paul here points out that doing one’s best and having a zeal for God is not enough, and it is precisely our desire to make this enough that causes the gift of God to be the stumbling block it is. “Behold, I am laying in Zion a stone of stumbling, and a rock of offense; and whoever believes in him will not be put to shame.” I mean this is incredible. We are to believe in a rock of offense, a stone of stumbling. And what an offense it is! It offends our Old Adam right down to the core! How can God do it? How can God look at all my zeal for him, how can he look at all the good works I have done to try earn his good graces and turn up his nose at them by letting the no good scoundrel down the street into his kingdom when he has 5 children by four mothers? We are enraged when we ought to be rejoicing with angels. This is the great stumbling block. The Gentiles don’t pursue righteousness but attain it by faith. And all those intent on working for it, whether Jew or gentile find themselves outside of the grace of God, knocking at the gates of hell to let them in. No, it is our self-righteousness, our pride, our Old Adam that is most intent on working his way into heaven. And it is sin. It’s great to try keep God’s commandments, it is great to have a zeal for God. But when you think your best is enough to please God, and that God should count it as something you fail to comprehend the gravity of your sin, you fail to comprehend the need for the cross. The Jews had zeal, the Jews did their best to keep the commandments, but they let that get in the way of God’s grace. With Christ it is different. Christ bestows upon us his grace, the word of God by which man lives, and in this grace we let love, which is not arrogant or rude, we let love take hold. This love washes over us in the waters of baptism like a spring rain that brings to life the flowers of the plain. In this grace we live to love, and love to live because he first loved us, the stumbling block laid in Zion that saved the scoundrel down the street, and more than that, even saved you with your hard heart.