1. History is the unfolding of God’s providence. So, the one who studies history is a student of God’s own mind as it has unfolded in each successive generation. In that sense, the study of history ought to be an act of worship that beholds God’s intention to preserve the seed of the woman from the seed of the serpent, both in terms of the preservation of biblical ideas, and of a visible people.
2. History holds the wisdom of ages past. The theologian who studies church history is able to appropriate the wisdom of the some of the greatest teachers who have ever graced the church. It is nothing but unbridled hubris for a theologian to undertake the study of Scripture and theology without consulting the gifted teachers of the past. Theologians who place their distinctive ideas and theological formulas on the level of historically accepted consensus risk making shipwreck on the same errors and heresies against which the earlier generations had to contend.
3. It gives its students a healthy sense of skepticism about things "novel." A person familiar with the history of ideas is in a position to see that there is nothing new under the sun. There may be new combinations of ideas and different ways of arriving at them and employing them, but the ideas heralded as “new” are really nothing new at all, and they carry with them the same power and baggage as they always have.
4. It provides a sense of context for contemporary ideas. The historian gains a sense of the way that contemporary ideas and beliefs are rooted in the past. Knowing the history of contemporary ideas allows us to see how they have been beneficial historically, but it can also shine light on unwelcome influences that may need to be purged, as well as warn against potential abuses of those ideas.
Can you think of any others?