In its primary sense, the word of God is none other than God. This is supported by the first verses of the gospel of John, where it is written that “in the beginning was the Word, and the Word was with God, and the Word was God.” The bible itself declares that, strictly speaking, the Word of God is none other than God the Son, the Second Person of the Trinity, the Word who was made flesh and dwelt among us.
Therefore, when God speaks, we are not simply given information; also, and above all, God acts. This is what is meant in the book of Genesis, where the Word of God is a creating force: “God said, let there be … and there was.” When God speaks, that which is uttered is also created. God’s Word, besides telling us something, creates something in us and in all creation. That creative and powerful Word is Christ, whose incarnation is both God’s greatest revelation and God’s greatest action. In Jesus, God was revealed to us. And also in Jesus, God overcame the powers of evil that held us in subjection. God’s revelation is also God’s victory.
Anyone who reads the Bible and somehow does not find Jesus in it, has not encountered the Word of God!
Justo L. Gonzalez on Martin Luther’s doctrine of the Word from his book “The Story of Christianity: Volume II – The Reformation to the Present Day” on pages 47-48
Some people have said law and gospel “is just a Lutheran axiom.” Martin Luther was without a doubt one of the most influential spokesman God used to teach the world about the double use of the law in his commentary of Galatians.
However, “when discussing Law and Gospel in connection with systematic or dogmatic theology [John Calvin] is in perfect agreement with Luther’s approach.” Calvin is one of many in the Reformed tradition who is in agreement with Luther.
Zacharius Ursinus, the primary author of the Heidelberg Catechism, states: “The doctrine of the church consists of two parts: the Law and the Gospel; in which we have comprehended the sum and substance of the sacred Scriptures…The law and gospel are the chief and general divisions of Holy Scriptures.”
Additionally, in Louis Berkhof’s “Systematic Theology” he explains this was the norm ever since the Reformation began. “The churches of the Reformation from the very beginning distinguished between the law and the gospel as the two parts of the Word of God as a means of grace.”
This preaching continued from some of the great Puritan preachers like Richard Sibbes, Thomas Cartwright, Thomas Watson, John Owen, and Thomas Goodwin. [The law-gospel distinction] is replete in the sermons and theological treatises of Episcopal Puritans such as Perkins, Richard Sibbes, and Archbishop Ussher; Presbyterian Puritans such as Thomas Cartwright and Thomas Watson; and Independents such as John Owen and Thomas Goodwin.”
In 1884 to 1885, every Friday evening C.F.W. Walther gave lectures on preaching that have now been published and become a classic work for those in Lutheran and Reformed churches. Walther may have said it best, “The true knowledge of the distinction between the Law and the Gospel is not only a glorious light, affording the correct understanding of the entire Holy Scriptures, but without this knowledge Scripture is and remains a sealed book.”