You might find this selection from Kretzmann’s Popular Commentary helpful:
An Exhortation to Progress and Steadfastness in the Faith. Heb. 6, 1-20.
Christians should make progress in knowledge: V.1. Therefore, leaving the principles of the doctrine of Christ, let us go on unto perfection, not laying again the foundation of repentance from dead works and of faith toward God, v.2. of the doctrine of baptisms and of laying on of hands, and of resurrection of the dead and of eternal judgment. V.3. And this will we do if God permit. The inspired writer continues the digression which began chap. 5, 11, in which he administers a sharp rebuke on account of spiritual sluggishness, warns against apostasy from the faith, and exhorts his readers to strive with great earnestness for the further growth and secure retention of the full certainty of their Christian hope. The first words of this chapter substantiate the last remark of the preceding chapter: Wherefore, leaving the doctrine of the beginning of Christ behind, let us be carried on to perfection, not laying the foundation over again of repentance from dead works and faith in God, of the doctrine of baptisms, of the laying on of hands, of the resurrection of the dead, and of eternal judgment. Because the Jewish Christians of Palestine, in spite of the many advantages they had enjoyed, were yet so sluggish in spiritual matters, and because, on the other hand, it could well be expected of them that they should leave behind them the state of spiritual childhood and immaturity, therefore the writer includes this exhortation. They were to leave the elements, the fundamentals of the Christian doctrine behind them and pass on to perfection. To this state they should permit themselves to be carried forward, they should surrender to the influence of the Word in its action upon their heart and mind, their will and their intellect. It should not be necessary again and again to lay the foundation of repentance and faith, and of all the simple instruction with which they might be expected to be familiar by this time.
This point is now analyzed. Repentance from dead works, as produced in men that are themselves spiritually dead, faith in Jesus Christ as the only way to salvation, the doctrine of baptisms, of Christian Baptism in its relation to Jewish washings, 1 Pet. 3, 21, of the laying on of hands in the case of the newly baptized, in order to transmit to them the gift of the Holy Ghost, Acts 8, 17-19; 19, 6, of the resurrection of the dead, and of the eternal judgment: all these are the material of which the foundation of Christian knowledge is composed and upon which Christian perfection is based. This material is divided into three groups, joined as pairs, the first two designating the fundamental demand of the Christian life, the next the beginning, the last its object or goal. Repentance and faith are the prerequisites for the Christian life; they mark a person’s turning from spiritual darkness to the light of God’s grace in Christ Jesus. Through Baptism the convert became a member of the Church, receiving also, through the laying on of hands, such endowments as fitted him for service in the house of God. He looks forward, finally, to the resurrection of the dead and the last judgment; for this signifies to every believer the consummation of the glory which shall never end. With encouraging frankness the writer adds: And this we shall do if the Lord permits. He wants to press on toward perfection, to the maturity which was fitting for Christians that had had the advantages which his readers had enjoyed. At the same time he knows, not only that his success in this venture depends entirely upon God’s will, but also that it is by no means self-evident that God will permit this plan to be carried out. There may be difficulties of a very peculiar nature in the way, which might hinder the project altogether, as becomes evident in the next paragraph.
The authorship of Hebrews is uncertain. It has always been classed with the “antilegomena”, those books in the NT whose apostolic authorship is uncertain— literally “has been spoken against.” This is simply a matter of historical fact. Origen famously wrote of the epistle: “Men of old have handed it down as Paul’s, but who wrote the Epistle God only knows.” Only the Church of Rome has presumed (in its typical arrogant manner) to dogmatize on this question, pronouncing “infallibly” that the author of Hebrews is the Apostle Paul. For more on this see this piece: “A blurb from Fr Charles on the canon of Scripture”
“Dead works” does not refer just to the sacrificing of animals per se; it refers to all of man’s attempts at self-justification, i.e., it refers to “works-righteousness,” as Hebrews 9 says: “The blood of Christ, who through the eternal Spirit offered Himself without spot to God, purges your conscience from dead works to serve the living God.”
“Therefore, leaving the discussion of the elementary principles of Christ, let us go on to perfection.” In this context, perfection refers to “completion,” i.e., having a fuller knowledge of the faith, participation in the life of Christ in and through the communion of saints. It means gradually attaining to “the unity of the faith and of the knowledge of the Son of God, to a perfect man, to the measure of the stature of the fullness of Christ” (Eph. 4:13)— not in the hope of earning salvation, for that has already been accomplished and we cannot add to it; no, but because this is what we were created for, and, having destroyed ourselves, it is what we have been graciously re-created for.
But that’s not the main question in the discussion of Hebrews 6. The question is: “What are the elementary principles?” The text answers this: “not laying again the foundation of repentance from dead works and of faith toward God, of the doctrine of baptisms, of laying on of hands, of resurrection of the dead, and of eternal judgment.”
What is the foundation of the Christian faith? St. Peter says it well: “Repent and be baptized, every one of you, for the forgiveness of your sins, and you will receive the gift of the Holy Spirit.” We don’t need to lay this foundation again. “Remember your baptism” doesn’t mean “Get baptized again”; the repentance of the Christian within his life life in Christ is not the same as the repentance of one’s initial conversion, in which man is granted faith and a new heart (i.e., is regenerated) by the Holy Spirit, in which one goes from being an unbeliever to being a believer, from being a child of Satan to a child of God. To deny this and say that there is no difference is to sneak the thin end of the pope’s uncertainty-wedge back into the apostolic faith: where is your assurance then?
Of those who repetitively “lay again the foundation of repentance from dead works and of faith toward God,” who only preach “about the forgiveness of sin and whatever else can be said about the doctrine of redemption,” Dr. Luther has this to say:
…But they flee as if it were the very devil the consequence that they should tell the people about the third article, of sanctification, that is, of new life in Christ. They think one should not frighten or trouble the people, but rather always preach comfortingly about grace and the forgiveness of sins in Christ, and under no circumstance use these or similar words: ‘Listen! You want to be a Christian and at the same time remain an adulterer, a whoremonger, a drunken swine, arrogant, covetous, a usurer, envious, vindictive, malicious, etc.!’ Instead they say, “Listen! Though you are an adulterer, a whoremonger, a miser, or other kind of sinner, if you but believe, you are saved, and you need not fear the Law. Christ has fulfilled it all!…They may be fine Easter preachers, but they are very poor Pentecost preachers, for they do not preach… ‘about the sanctification by the Holy Spirit,’ but solely about the redemption of Jesus Christ, although Christ (Whom they extol so highly, and rightly so) is Christ, that is, He has purchased redemption from sin and death so that the Holy Spirit might transform us out of the Old Adam into New Men…Christ did not earn only gratia, grace, for us, but also donum, ‘the gift of the Holy Spirit,’ so that we might have not only forgiveness of, but also cessation of, sin. Now he who does not abstain from sin, but persists in his evil life, must have a different Christ — that of the Antinomians; the real Christ is not there, even if all the angels would cry, ‘Christ! Christ!’ He must be damned with this, his new Christ. (On the Council and the Church, Luther’s Works, ed. Jaroslav Pelikan; CPH: St. Louis, 1964, 1992; 41:114)
This does not mean that we stop needing the forgiveness of sins as it is declared to us in absolution and preaching and administered to us in the Eucharist. No— we always need it: we never stop needing imputation. But Christ’s grace, though it is always extra nos, is not only extra nos: it starts outside of us, never within us, but it does indeed permeate us, changing us and remaking us in the Divine Image which was lost because of sin. As Luther says, “[Christ] has purchased redemption from sin and death so that the Holy Spirit might transform us out of the Old Adam into New Men…Christ did not earn only gratia, grace, for us, but also donum, ‘the gift of the Holy Spirit’…” That’s right— the Spirit departed from man at the Fall, but when we are created anew in baptism, He is breathed back into our nostrils, just as God enlivened the man of dust in the garden and made him a living creature.
Many former evangelicals who have become Lutherans were so horsewhipped with the Law, so burned by a constant barrage of demands to “measure up”, “not be a backslider”, “prove your faith”, etc., that when they come into Lutheranism, they quite understandably have an intense phobia of any talk of growth, striving, improvement, personal holiness, etc. They try to read Scripture as though it doesn’t talk about any such things at all. Quite often, they gravitate towards what has been termed “Radical ‘Lutheranism'”— as you can see, I cannot qualify this via scare-quotes enough— or, more often, they hove into some “lite” iteration of it which can be found braying enthusiastically (and often sarcastically) on the internet. It is a sad state of affairs that many are brought into the Lutheran Church under false pretenses, as though Lutheranism were simply “anti-evangelicalism.” There is actually more to our church than that. Just remember: if something sounds “too good to be true,” sometimes there’s a good reason for that, i.e., it’s not actually true. (Have you ever noticed that we’re less likely to exclaim, “That’s too bad to be false”?)
Lastly, there is a way in which even the term “confessional” has become something of a shibboleth: do not assume that because somebody identifies as a “confessional Lutheran”— frequently and loudly— that the theology they promote resembles that of the Lutheran Confessions. Increasingly, loud and proud identification as a “confessional Lutheran” means little more than, “I’m not one of those pietist evangelicals.” Or, perhaps more piquantly put: “I thank thee, Lord, that I am not like the evangelicals.” Something like that. But this is a sad substitute for the richness of the Lutheran tradition, and, sadly, it is often simply trading one set of malicious and unscriptural falsehoods for another.
Merry Christmas, brother.