Nearly all the peculiar opinions of the Jews the apostle had overthrown in his previous argument. Here he gives the finishing stroke, and shows that the tendency of the law, as a practical matter, was everywhere the same. It was not, in fact, to produce peace, but agitation, conflict, distress. Yet this was not the fault of the law, which was in itself good, but of sin, Rom 7:6-24. I regard this chapter as not referring exclusively to Paul in a state of nature, or of grace. The discussion is conducted without particular reference to that point. It is rather designed to group together the actions of a man's life, whether in a state of conviction for sin or in a state of grace, and to show that the effect of the law is everywhere substantially the same. It equally fails everywhere in producing peace and sanctification. The argument of the Jew respecting the efficacy of the law; and its sufficiency for the condition of man, is thus overthrown by a succession of proofs relating to justification, to pardon, to peace, to the evils of sin, and to the agitated and conflicting moral elements in man's bosom. The effect is everywhere the same. The deficiency is apparent in regard to ALL, the great interests of man. And having shown this, the apostle and the reader are prepared for the language of triumph and gratitude, that deliverance from all these evils is to be traced to the gospel of Jesus Christ the Lord, Rom 7:25
The apostle had, in the preceding chapter, shown the converted Gentiles the obligations they were under to live a holy life, addresses himself here to the Jews who might hesitate to embrace the Gospel; lest, by this means, they should renounce the law, which might appear to them as a renunciation of their allegiance to God. As they rested in the law, as sufficient for justification and sanctification, it was necessary to convince them of their mistake. That the law was insufficient for their justification the apostle had proved, in chapters iii., iv., and v.; that it is insufficient for their sanctification he shows in this chapter; and introduces his discourse by showing that a believing Jew is discharged from his obligations to the law, and is at liberty to come under another and much happier constitution, viz. that of the Gospel of Christ, Rom 7:1-4. In Rom 7:5 he gives a general description of the state of a Jew, in servitude to sin, considered as under mere law. In Rom 7:6 he gives a summary account of the state of a Christian, or believing Jew, and the advantages he enjoys under the Gospel. Upon Rom 7:5 he comments from Rom 7:7-25, and upon Rom 7:6 he comments, Rom 8:1-11.
In explaining his position in Rom 7:5 he shows:
We were buried therefore with him by means of baptism unto death (sunetaphêmen oun autôi dia tou baptismatos eis ton thanaton) second aorist passive indicative of sunthaptô, old verb 'to bury together with' (only here and Col 2:12). With associative instrumental case (autôi) and "by means of baptism unto death" (from preceeding verse). In newness of life (en kainotêti zôês) The picture in baptism points two ways: backwards to Christ's death and burial and to our death to sin (cf. Rom 6:1), forwards to Christ's resurrection from the dead and to our new life pledged by the coming out of the watery grave to walk on the other side of the baptismal grave. There is the further picture of our own resurrection from the grave. It is a tragedy that Paul's majestic picture here has been so blurred by controversy that some refuse to see it. It should be said also that a symbol is not the reality, but the picture of the reality.
Obviously, you do not believe that baptism is a means of grace, that it is a sacrament. I do believe that it is and that my Lutheran theology agrees with St. Paul's.
BTW, "sacramentarian" historically was the term used to describe those who held to a non-sacramental view of the Lord's Supper, i.e., the Zwinglians and Calvinists, who denied the real presence of Christ's Body and Blood in the Sacrament.