In the reading plan that I am following, the introduction to the Saul of the Old Testament (1 Samuel 9-10) and the introduction to the Saul of the New Testament (Acts 8, including Acts 7:58) occur on the same day's reading. So naturally I have been thinking about how the two Sauls compare to each other. I even wonder if Paul's parents may have given him the Jewish name of Saul in honor of the ancient king, considering that Paul's family descended from the same tribe as Saul - Benjamin (Phil. 3:5).
The Saul of the OT is presented to us as the epitome of what a great king should be. He was good looking, and was an impressive physical specimen, standing head and shoulders above all Israel (a fact that is stated twice - in 1 Sam. 9:2 and 1 Sam. 10:23). On this basis he appeared to be the perfect match for Israel's desire for a king who could go out before them and fight for them (1 Sam. 8:19-20). But as we will see, after some initial victories, Saul quickly reveals an inner character of a completely different quality than his outward appearance. He lacked faith in God and failed to obey His word, and as a result his reign proved disastrous to Israel and ultimately fatal to him and his family.
In contrast, the Saul of the NT is introduced to us as a violent opponent of Christianity. He endorsed the brutal murder of Stephen, and then took matters into his own hands to ravage the church. On the surface, it was as unlikely that this Saul would become an apostle of Jesus as it was that his OT namesake would become a maniacal failure. Both Sauls were radically transformed, though in vastly different trajectories.
I have known people who had every possible reason to turn out to be great servants of the Lord - godly and caring parents, supportive and nurturing congregations, faithful and dedicated friends - only to make shipwreck of their faith. And on the other hand, I have known people who had every possible reason to be hostile to the faith or reckless in their way of life, only to become tenacious disciples of the Lord. We all have tremendous capacity for transformation, and if we are to make sure that transformation is from glory to glory, like the Saul of Acts we must always have a clear vision of Jesus in our heart.