Introduction to One Samuel
by Dr. Henry M. Morris:
(taken from the Defender's Study Bible)
The two books of Samuel were originally one book in the ancient Hebrew Canon, but became two in the Greek Septuagint translation of the Old Testament. Samuel may be considered the last of the judges (1 Samuel 7:15). When he attempted to appoint his two sons as judges to succeed himself (1 Samuel 8:3), they proved unworthy, and the people demanded a king. The book of 1 Samuel is thus especially significant in describing Israel's transition from a theocracy to a monarchy.
In addition to being a judge, Samuel was also a priest (1 Samuel 7:9; 13:11-14) and prophet (1 Samuel 3:20). He was probably the founder of the so-called “school of the prophets,” which proved so important in Judah and Israel for centuries to come (1 Samuel 19:20). He was never king of Israel, but did have the privilege of being used by God to anoint as king first Saul, then David.
Samuel possibly wrote the first twenty-four chapters of the book himself, but he could not have written more than this, as the events of 1 Samuel 25-31 occurred after his death (1 Samuel 25:1). It is possible that the prophets Nathan and Gad, who were probably trained by Samuel, wrote these later chapters, as well as all of 2 Samuel (note 1 Chronicles 29:29). The final author or editor is unknown, however, and it may be that whoever it was simply used the earlier records of Samuel, Nathan and Gad in compiling his own account under divine inspiration. Even 1 Samuel could not have been put in its final form until at least the days of Rehoboam, for the kingdom had already been divided by the time this was done (note 1 Samuel 27:6).
Just as Moses had placed his books of the law in the Ark of the Covenant to be preserved there (Deuteronomy 31:24-26, so probably did Joshua (Joshua 24:26) and also Samuel (1 Samuel 10:25). Accounts were kept of the events in the life of David (1 Chronicles 27:24), and it is at least possible that these were kept by Nathan and/or Gad, both of whom outlived David.
In any case, there is every reason to believe that we have actual eye-witness accounts of the events described in both 1 Samuel and 2 Samuel. This was an extremely important period in the economy of Israel, marking both the great revival under Samuel after the dark period of the later judges, especially Eli. The period also contains the transition of the united kingdom under David and Solomon, the time of Israel's pinnacle of greatness in all its history to date.