J.I. Packer's view of
Luther's Theology
J.I. Packer is a well-known writer of classical Reformed (Calvinist) books. He is of the opinion that Luther's basic theological position was essentially Calvinist.
A quote from J. I. Packer & O. R. Johnston, The Bondage of the Will (page 58):
"The doctrine of free justification by faith alone, which became the storm center of so much controversy during the Reformation period is often regarded as the heart of the Reformers' theology but this is not accurate. The truth is that their thinking was really centered upon the contention of Paul, echoed with varying degrees of adequacy by Augustine, and Gottschalk, and Bradwardine, and Wycliffe, that the sinner's entire salvation is by free and sovereign grace only. The doctrine of justification by faith was important to them because it safeguarded the principle of sovereign grace; but it actually expressed for them only one aspect of this principle, and that not its deepest aspect. The sovereignty of grace found expression in their thinking at a more profounder level still in the doctrine of monergistic regeneration – the doctrine, that is, that the faith which receives Christ for justification is itself the free gift of a sovereign God, bestowed by spiritual regeneration in the act of effectual calling."
This is a clear statement of a Calvinist's position, but it not Lutheran, nor do I believe it was Luther's. Lutheran theology is focused on the cross as the center of all understanding of God. One level out from that is an examination of the faith that trusts in the cross. Another level out is the understanding of how God has chosen some to receive this faith. The Calvinists reverse this order.

Dr. Packer has a practice of insisting that Luther had the same theological positions as Calvin, although he admits they differed on minor points like the real presence of Christ's body and blood in the Lord's supper and a different view of baptism. Dr. Packer states, in The Bondage of the Will (page 204),
Writing to Capito on July 9th, 1537, with reference to a suggested complete edition of his works, he roundly affirmed that none of them deserved preservation save the little children's Catechism and The Bondage of the Will; for only they, in their different departments, were 'right' (justum)".
However, in that Small Catechism, Luther firmly states that salvation is received through the sacraments.
What benefits does Baptism give?
It works forgiveness of sins, rescues from
death and the devil, and gives eternal salvation to all who believe
this, as the words and promises of God declare.
Referring to the Lord's Supper:
What is the benefit of this eating and drinking?
These words, "Given and shed for you
for the forgiveness of sins," show us that in the Sacrament forgiveness
of sins, life, and salvation are given us through these words. For where
there is forgiveness of sins, there is also life and salvation.
This does not fit with Calvinistic theology's view of salvation. How is that so? It is so, because the cross is central to Lutheran (and Luther's) theology. Reading Luther's "The Bondage of the Will" leads Calvinists (like Dr. Packer) to believe that Luther would also have applied the logical conclusions of a belief that if God is entirely responsible for our salvation, he would not start salvation in a person and not bring it to completion, hence the doctrine of Preservation. However, Lutherans (and Luther) do not make that logical conclusion because it goes beyond what the Bible asserts for the reason that it distracts from a theology based upon the cross. The doctrine of Preservation serves a theology (Calvinistic) that seeks to understand the entire purposes of God in the world and proclaims this to be the profoundest level, as Dr. Packer did.
Luther was so adamant about his understanding of the Lord's Supper not because it was an isolated theological point, but because it reflected his theology that was centered in the cross.
Dr. Packer has misrepresented Luther's position in other writings also, such as in his book Knowing God:
"Like all later Lutherans, however – though not like Luther himself! – Wesley held that assurance relates to present acceptance by God only, and that there can be no present assurance of persevering."
Lutherans certainly don't believe what Wesley believed. Dr. Packer, and unfortunately most Reformed church and Evangelical church theologians seem unable to understand the Lutheran position. It is as if scales cover their eyes. Lutherans do not believe that our salvation depends upon our lives at all. Any look at ourselves, including whether we would persevere, is seen as part of the law. The law only to drives us to the gospel of the cross again. Any look inward at ourselves or at our lives will reveal sin and death. A look outward to the cross reveals life and salvation.
Evidently, Dr. Packer feels that he can make a stronger case for Calvinism with the support of Luther. However, the writings of Luther have been very thoroughly researched by Lutherans through the ages and I feel that he, like most other reformed theologians is just unable to understand Luther's (and Lutheran) theology.
Knowing that not everyone will inherit eternal life, all flavors of Reformed theology seem determined to arrive at a way to base assurance of salvation upon what happens in our lives (as a way to differentiate us from those who will go lost), instead of upon just the cross. But any turn of our spiritual eyes from the cross to our lives is spiritual death. Only a turn from our lives to the cross is life and salvation.