What is the real reason for writing history, specifically as a Christian? It might be helpful to start with one man's answer.
In introducing The Bruce—an epic, 14th-century historical poem—John Barbour suggested three reasons. A story in and of itself gives pleasure, but a well-told story ("said on gud maner") serves up twice the pleasure. Pleasure comes from the narrating ("the carpyng") and from learning what actually happened ("the thing rycht as it wes"). The third reason is to honor and praise the dead and their good deeds ("suld weill have prys"). Entertain, gratify curiosity, and honor our ancestors—that's it. Not a whiff of providentialism. And to think, Barbour the historian was not only a Christian but a clergyman.
Tim Stafford does well to bring a similar discussion of Christian historiography—how Christians write history, their philosophy and methodology—to the readers of Christianity Today (April 2, p. 42). On the one side you have an ambitious cadre of evangelical historians, like George Marsden, who in their specialties dominate the study of American church history. They are writing what they and Stafford call "ordinary" history, which to some looks more or less secular. On the other, you have those who argue that Christian history should be more explicitly Christian. The former rule the conversation and balk at their detractors, the "providentialists."
I actually lifted that example of The Bruce from another discussion of how Christians write history. The author is not Mark Noll, Marsden, or Nathan Hatch. It's C. S. Lewis. His treatment of historiography in The Discarded Image: An Introduction to Medieval and Renaissance Literature is, as expected, timely, even-handed, erudite.