The 500th Anniversary of Luther posting 95 thesis on the door of the Wittenberg Church has prompted the Adventist Church to initiate the study of two books of the Bible which were key sources enabling Luther's rise out of the darkness of spiritual fear and despair into becoming a champion promoting "salvation in Christ".
In 1515 (that's two years prior to posting his 95 thesis) Martin Luther, who was now a professor of Theology at the University of Wittenberg, began a course of lectures on the book of Romans.
Like all teachers who painstakingly prepare their lessons, he benefited greatly from this preparation as he pondered and compared the scriptures, seeking to make them clear to his students.
Here is the first paragraph to the preface to his study of Romans:"The Epistle is really the chief part of the New Testament and the very purest Gospel, and is worthy not only that every Christian should know it word for word, by heart, but occupy himself with it every day, as the daily bread of the soul. It can never be read or pondered too much, and the more it is dealt with the more precious it becomes, and the better it tastes."
You can read the rest of his preface
HERE In it he defines the words: law, sin, grace, faith, righteousness, flesh, Spirit
and concludes with --
"Without this understanding of the terms noted you will never grasp this epistle of St. Paul, nor any book of the Holy Scriptures. Therefore, beware of all teachers who employ these words in a different sense, no matter who they are, even if they should happen to be Jerome, Augustine, Ambrose, Origen, and men like them or still higher than they."
Semantic confusion is the foundation of theological confusion.