One of the problems with the account of Saul’s life in the Book of Samuel is that it seems pretty clear that the narrator wants the reader to conclude that Saul was a bad king, so bad in fact that God needed to replace him with David. Why is this a problem? There is evidence in Samuel itself which suggests that in many ways Saul was a good king, so good in fact that when we weigh that evidence we might begin to wonder why he was judged so harshly. Let’s look at some of the evidence.
First, Saul was militarily successful against Israel’s foes and 1 Samuel 13:2-14:48 gives a fairly lengthy account of some of his military achievements concluding with “When Saul had taken the kingship over Israel, he fought against all his enemies on every side—against Moab, against the Ammonites, against Edom, against the kings of Zobah, and against the Philistines; wherever he turned he routed them. He did valiantly, and struck down the Amalekites, and rescued Israel out of the hands of those who plundered them.” Being a good military leader was, after all, one of the primary reasons the people wanted a king: ” …. that our king may govern us and go out before us and fight our battles” (1 Samuel 8:20). So apparently Saul did exactly what he was chosen to do.
Second, even David noted that Saul’s reign brought prosperity for Israel. Prosperity is typically a consequence of a relatively peaceful and stable time. In David’s lament over Saul and Jonathan he acknowledged that Saul “clothed you [Israel] with crimson, in luxury, [and] put ornaments of gold on your apparel” (2 Samuel 1:24). This is high praise for a king who made his people wealthy. David also describes Saul as “the glory [or beauty] of Israel,” praises his military prowess, and his grief for Saul and Jonathan appears to be genuine. Saul’s death was a real loss for Israel.
Third, Saul had a reasonably long reign and this seems to be at odds with the judgment relatively early in his reign that “The LORD would have established your kingdom over Israel forever, but now your kingdom will not continue“ (1 Samuel 13:13-14). His kingdom did in fact continue for some time, although we don’t know exactly how long he reigned because of a textual corruption in 1 Samuel 13:1. Some English translations (including NRSV) have “Saul was . . . years old when he began to reign; and he reigned . . . and two years over Israel.” What’s going on here? The “…” highlights the fact that something is missing in the Hebrew. The NRSV has a footnote which explains that in the first case the number is lacking in the Hebrew text (the verse is lacking in the Septuagint) and in the second case “two is not the entire number; something has dropped out.” The ESV has “Saul lived for one year and then became king, and when he had reigned for two years over Israel …” while KJV has “Saul reigned one year; and when he had reigned two years over Israel …” The ESV is clearly wrong as Saul could not possibly have begun to reign when he was one year old, and the events which follow could not have taken place when he was three! The KJV’s “Saul reigned one year” doesn’t correctly represent the Hebrew, and doesn’t even make sense when it’s followed by “and when he had reigned two years.” The NET Bible has “Saul was [thirty] years old when he began to reign; he ruled over Israel for [forty] years.” This makes better sense, but where did those numbers in brackets come from? As the NRSV footnote has correctly noted, this verse is missing in most of the Greek manuscripts (the Septuagint), although a few manuscripts do have the verse with “thirty years” here (although some others have “one year” like the Hebrew). The Syriac Peshitta has Saul’s age as twenty-one, but lacks the next part of the verse with how long he reigned. It looks like these Greek and Syriac translations recognised that something was wrong, or missing, and tried to correct it, but they arbitrarily came up with different numbers. According to the New Testament (Acts 13:21) Saul reigned for forty years, but this could be a rounding (the Hebrew has “… and two” so it could be a rounding down from “forty two” and some English translations do in fact take it this way and have “forty two” in Acts 13:21). It’s a mess! We can only speculate how, or why, this verse became corrupted. We simply don’t know from the Hebrew how long Saul reigned, but from the descriptions of his military campaigns we can deduce that it was a reasonably long reign. If God was so displeased with Saul that he wanted him gone, why did he allow him to carry on for several more decades?
Fourth, after Saul’s death his son Ish-bosheth (known in Chronicles and in some English translations of Samuel as Eshbaal/Ishbaal) was crowned as king of Israel (2 Samuel 2:10). The tribe of Judah then seceded from the kingdom of Israel and installed David as their king, which led to civil war (2 Samuel 3:1). Ish-bosheth was assassinated after a two year reign by two men who hoped to get a reward from David (although David actually had them executed, 2 Samuel 4:5-12), thus ending “the House of Saul” as a dynastic monarchy. We shouldn’t read too much into Ish-bosheth’s succession but it does suggest that the people (with the exception of the tribe of Judah) were happy to continue to be ruled by the House of Saul, and, by inference, the people were therefore happy with Saul’s reign.
One Samuel scholar, Rachelle Gilmour, has noted that in the Book of Samuel Saul “is tested and scrutinised in a way that David is not” and points out that even some of his positive characteristics, such as listening to the people, are portrayed in Samuel as weaknesses.  She further argues that “Saul’s infraction is at most a minor misunderstanding, and he is held to account for a command that is only fully explained to him after he has transgressed it.” I’ve previously noted that Saul’s making an ‘unlawful sacrifice’ is said to be the reason why God would thereafter remove him as king of Israel and put another king in his place (1 Samuel 13:8-14). He didn’t break any biblical commandments, he simply allegedly failed to follow a specific instruction by Samuel (and Gilmour regards this as a genuine misunderstanding on Saul’s part). On the other hand, David committed adultery and murder, both serious breaches of God-given commandments, and arguably broke other commandments such as the prohibition on non-priests from eating the bread in the tabernacle, without losing his kingship. Why was Saul judged more severely than David when his misdemeanours were relatively minor compared to David’s crimes?
If Saul was indeed a good king who delivered Israel from its enemies, brought stability and prosperity to the nation, and reigned unopposed for a long time, why is he portrayed in a bad way by the Book of Samuel? Remembering that after two generations the northern tribes seceded from David’s united kingdom and thereafter re-established a northern monarchy (albeit not a Saulide one), we should conclude that the seeds of a divided Israel were there from the beginning, even before David became king. The Book of Samuel is southern, Judahite, political propaganda. Just as the Book of Kings condemns all the northern kings, regardless of whether they were good or bad, so the Book of Samuel condemns Saul and his family who were based in the north. At one redactional level this was almost certainly done by supporters of David and his dynasty: material which made Saul look bad was inserted into the record to make David look good, and to justify David’s conquest of the north. However, at another (later) level the record was edited to reflect an anti-monarchist position which argued that all kings were bad, Saul, David and Solomon included. It was probably at this time that the stories of David’s adultery with Bathsheba and his murder of her husband Uriah were added. Trying to unravel the various redactional layers in Samuel is a complex process, but by understanding that Samuel-Kings was dynamic literature which was continually changing and shifting with the political and theological ideas of its writers and editors helps us to make better sense of the contradictions and why some characters seem to be both heroes and villains.
 Gilmour, Rachelle, “Saul’s Rejection in the Book of Samuel.” Pages 90-117 in Divine Violence in the Book of Samuel. New York: Oxford University Press, 2022.