Contemporary Lutherans seem almost afraid of the word "sanctification" or of the concept of the third use of the Law. It is feared that any talk of progress in the Christian life leads into Evangelicalism, Reformed Theology, or even Pietism. Preaching must always utilize a Law-Gospel paradigm without any exhortation unto good works. Remind the people of their sin, then of there savior, that's all. I even heard a Pastor recently say that the Christian can do no good, only evil.
I didn't see this when I first became a Lutheran, because I was only concerned to hear about the gospel rather than being beaten by the Law each Sunday like I was at Reformed Churches. Yet, after some time in Lutheran churches, and in Lutheran circles I began to see that progressive sanctification is neglected, often denied altogether. As I read through Luther, Chemnitz, Walther, Krauth, Pieper and others, I saw a great incongruity between what these classical sources said and what was being taught as Lutheran theology. These classical sources talked a lot about good works, progressive sanctification, and even give advise as to how to avoid specific sins. I fear that if these figures were around today they would be labeled "legalists" or "pietistic."
This type of teaching has practical consequences. I know of Lutheran pastors, theologians, and lay people who use as course language as they can, drink excessively, watch pornography, blow smoke in people's faces who don't approve of the act, just to proclaim their "Christian liberty." I don't think this is what Luther or Paul had in mind when they discussed the concept. I seem to remember someone answering the question, "Shall we sin that grace may abound?" with the answer "by no means!", or as the Cotton patch paraphrase puts it: "Hell no!" I think many Lutherans today would answer that question by saying "of course!"
Progressive sanctification is taught in our Confessions. For example,
"This faith is the true knowledge of Christ; it uses the benefits of Christ, it renews hearts, and it precedes our fulfillment of the law." Ap. IV.46
"To be justified means that out of unrighteous people righteous people are made or regenerated, it also means that they are pronounced or regarded as righteous." Ap. IV. 72
"Faith truly brings the Holy Spirit and produces a new life in our hearts, it must also produce spiritual impulses in our hearts." Ap. IV. 125
"Therefore Paul states that the law is established, not abolished, through faith, because the law can be kept only when the Holy Spirit is given." Ap. IV. 132
"We openly confess, therefore, that the keeping of the law must begin in us and then increase more and more." Ap. IV. 136
"Since this faith is a new life, it necessarily produces new impulses and new works." Ap. IV. 250
"Furthermore, we also say that if good works do not follow, then faith is false and not true." SA 13.3
"Here, then, we have the Ten Commandments, a summary of divine teaching on what we are to do to make our whole life pleasing to God. They are the true fountain from which all good works must spring, the true channel through which all good works must flow." LC First Part, 311
Note that Luther is willing to even admit that living by the Ten Commandments is pleasing to God- a phrase which I have heard condemned by a prominent Lutheran pastor.
"Meanwhile, because holiness has begun and is growing daily, we await the time when our flesh will be put to death, will be buried with all its uncleanness, and will come forth gloriously and arise to complete and perfect holiness in a new, eternal life." LC Second Part, 57
"But the Creed brings pure grace and makes us righteous and acceptable to God. Through this knowledge we come to love and delight in all the commandments of God because we see here in the Creed how God gives himself completely to us, with all his gifts and power, to help us keep the Ten Commandments: the Father gives us all creation, Christ all his works, the Holy Spirit all his gifts." LC Second Part, 69
"When we become Christians, the old creature daily decreases until finally destroyed." LC Fourth Part, 71
"Now, when we enter Christ's kingdom, this corruption must daily decrease so that the longer we live, the more gentle, patient, and meek we become, and the more we break away from greed, hatred, envy, and pride." LC Fourth Part, 65-67
These quotes could be multiplied, and I didn't even begin quoting the Formula. Good works are an essential part of Lutheran theology, as can be demonstrated here by the Confessions themselves. The believer is made a new creation by the waters of Holy Baptism. The Holy Trinity dwells within the Christian, causing him to love God and neighbor. This causes the Christian to obey God's commandments, and to daily increase in love of God and neighbor.
All of this should cause us even more to have a robust doctrine of sanctification. Through baptism, we truly are made new creatures. That should give us hope in the fact that we can begin to obey God's commandments, though imperfectly. Rather than using phrases like "weak on sanctification" or "sanctification is just getting used to justification", why don't we actually adhere to what our Confessions teach? Sanctification is a progressive reality, we are made to be like our Lord as our sinful natures are put to death and the new man arises.
The difference between the Lutheran and Reformed is not that the Reformed believe in progressive sanctification and personal holiness, but Lutherans don't. Rather, traditionally, the dividing line has been in terms of the prominence of certain teaching. In Lutheranism, justification predominates over sanctification, and the second use of the law over the third. Good works and sanctification always have to be taught in view of justification, in view of what God has done for us. However, that is not grounds for rejecting sanctification altogether.