Concerning the Content of “the Word of God”
The question that arises naturally from an examination of this distinction in the book of Acts between “the Word of God” and “the Scriptures” is: “Of what did this ‘Word of God’ consist? Could we understand the phrase to mean the entire content of the Gospels (in their prepublished, oral form)? Or should we, rather, understand ‘the Word of the Lord’/ ‘the Word of God’ to be restricted to the words of Christ’s Law teaching and Gospel teaching, and not to be inclusive of the biographical details given in the four canonical Gospels?’ We’ve already answered this question in its germinal form earlier when we described the Word of God, as it appears in Acts, to consist of teaching regarding the life of Christ as it stands in relation to OT Scriptures. What constitutes “the Word of God,” therefore, is historical exposition, if I may use the term loosely, that is proving from the Scriptures that what took place in the Gospels was the fulfillment of God’s Word to the ancient Jews. This means that “the Word of God,” in the book of Acts, consisted of (i.)the biographical details surrounding the Lord Jesus’ life (i.e. events, people, relationships, how He interacted with others, what He taught, etc), and (ii.)detailed exposition of the Old Testament in its fulfillment in Christ and all that doctrinally ensues therefrom. What is called the Word of God, therefore, is not simply the sayings of Christ collected into a book that has no narrative structure, but the very narratives contained in the four Gospels are presupposed in the phrases “the Word of God” and “the Word of the Lord” throughout the book of Acts. The entire life of Christ as recorded in the canonical Gospels is called “the Word of God” by the author of Acts.
Concerning Propositional Revelation
The question of whether or not we can understand these narratives to be God speaking, however, can be answered by pointing to how the writer of Hebrews speaks of the Old Testament. In Hebrews 1, the author attributes statements to God that, according to the original sources in question, are not stated by Him, but by others. Out of the seven citations, in fact, only three are given by God Himself, while the others are the words of the psalmist, etc. Yet, the apostle tells us that it is God who said these things. This is too wonderful for the faithless to comprehend, but by faith we understand that the writer of Hebrews is declaring that the Word of God is not just contained in the monologues, commands, and promises that God issues forth, but that it is also found in places in Scripture where God is not speaking directly (i.e. where a true prophet, psalmist, or narrator is also speaking). The writer of Hebrews, moreover, is not alone in doing this, for doesn’t Christ say “…He who created them made them male and female, and said, ‘Therefore a man shall leave His father and mother…[etc]’”? By stating that it is God who is speaking in Genesis 2:24, the Lord Jesus is doing what the writer to the Hebrews does in Hebrews 1, implying that it is not only the commands, promises, etc of God that count as the Word of God, but also the narratives themselves, in all of their exhaustive details, that constitute the Word of God.
 This may constitute an additional proof of the Deity of Jesus Christ, insofar as “the Word of the Lord” seems to be an obvious reference to the doctrines of Christ (cf. Matthew 28:19-20), and its synonym is “the Word of God.”
 An example of how the teaching/preaching of the apostles (i.e. the Word of the Lord/the Word of God as it was given by the apostles) included biographical details surrounding the life of the Lord Jesus can be found in Acts 2:36, and, in more detail, in Acts 3:13-15, which finds its correlative passages in Matthew 26:47-68; 27:1-2, 11-44, et al. Similarly, in Acts 13:23-39. This proves that the content of their teaching/preaching included narrative details that were not, technically, the doctrines of Christ as preached on the Sermon on the Mount, etc, but included the details surrounding His life, such as we find in the four Gospels.
 Two examples are Acts 2:14-41 and 13:23-39.