The purpose of theology (part 2)

Welcome to The Theology Whisperer, a series of short blog posts on theology and theological education.


In my previous post I suggested that one purpose of theology is to provide a coherent and consistent statement of truths, derived from Scripture. But there is more to theology.

Theology and making sense of our world

There is an internal purpose, enriching the worship of God and ministry in the church; and an external purpose, addressing the world of people and of ideas. Theology involves “reflection internal to the church’s labor … [on] speaking of the gospel, whether to the world as message of salvation or to God as appeal or praise.”[1]

Theology may serve an evangelistic or ecumenical purpose, inform interreligious dialogue, or defend against threats to truth. Theology enables critical reflection on, and cogent response to, the truth claims of alternative beliefs, both religious and secular; and to the many varieties of teaching, some mutually contradictory, which exist within Christianity.[2]

Theology also supports Christian approaches to philosophy, apologetics, ethics, public theology, and justice. It provides a basis for informed reflection on, and response to, the challenges of culture and philosophy. It enables understanding and exegesis of culture, since “the public world that faith inhabits confronts it with challenges and contradictions that cannot be ignored.”[3] Thus Plantinga et al write:

What are the pressing issues of the day? What are the questions being asked? What vocabulary is in vogue? Christian theology must take up these issues and address them in the language of the day … Such a task also involves showing the beauty and attractiveness of the Christian faith, suggesting it as a compelling way to see and live life.[4]

Thoughtful Christians therefore seek to develop their theological knowledge and skills in order to commend their faith to those outside the community of faith (mission); and to defend their faith against attack from inside or outside the church (apologetics) (1 Pet 3:15f).

Theology and growing as a Christian

Another important purpose of theology is to enrich Christian discipleship. Those who identify as Christians should seek daily to follow Jesus. Puritan theologian William Ames argued that theology is the doctrine of living to God.[5] It should serve practical, not merely speculative, ends.

Theology supports the practical dimension of faith by challenging us to go deeper, identifying why we hold our beliefs and to what degree those beliefs rest on biblical foundations:

It is very easy to rely on experience alone and assume that, if there is something we are unaware of, it probably does not matter. That is a great mistake. The Bible teaches us that we must not be content with what we already have but must go on to greater things, and theology is there to point the way to a more mature faith. Like the children we are, we constantly need to be challenged with the next hurdle, which we must overcome in order to grow.[6]

The temptation to intellectualise our faith is very real, and systematic theology may readily contribute to this distraction from growth in practical Christian discipleship. Such growth is facilitated by the application of biblical and theological knowledge, engagement in spiritual disciplines, and reliance on the Holy Spirit to transform us into the image of Christ.

Together, truth and experience greatly assist in developing an individual or community in pursuit of Christian discipleship. Truth affects and informs experience, and experience affects and informs our understanding of truth; but truth ought to remain primary because experience is necessarily subjective.[7]

John Calvin, one of the great theologians of the past 500 years, is primarily known for his biblical and systematic theology. It may seem that, for Calvin, getting to the truth was all that mattered. Yet while Calvin’s great theological treatise is regarded as a “classic statement of Protestant theology,” he did not call it a summa theologiae but a summa pietatis: “The secret of his mental energy lies in his piety; its product is his theology, which is his piety described at length.”[8]

Calvin defined piety as “that reverence joined with love of God which the knowledge of his benefits induces.”[9] Growth in Christian piety leads to good theology, which in turn strengthens and enriches piety.

More on this in my next post.


This post was written by Rod Benson. Leave a comment in the box below, or email 


[1] Robert W. Jenson, Systematic Theology. Volume 1: The Triune God (Oxford: Oxford University Press, 1997), 1:11.

[2] Millard J. Erickson, Christian Theology (3rd edition; Grand Rapids: Baker Academic, 2013), 16.

[3] Daniel L. Migliore, Faith Seeking Understanding: An Introduction to Christian Theology (3rd edition; Grand Rapids: Wm B. Eerdmans, 2014), 4.

[4] Richard J. Plantinga et al, An Introduction to Christian Theology (Cambridge: Cambridge University Press, 2010), 19.

[5] William Ames, The Marrow of Theology, (1639; repr. Durham, NC: Labyrinth Press, 1983), 1.1.1.

[6] Gerald Bray, God is Love: A Biblical and Systematic Theology (Wheaton: Crossway, 2012), 82.

[7] Erickson, Christian Theology, 15.

[8] John Calvin, Institutes of the Christian Religion (2 vols; ed. John T. McNeill; Library of Christian Classics, vol. XX; Philadelphia: Westminster Press, 1960), vol. 1, introduction, l.

[9] Calvin, Institutes, I.ii.1.

Image source: This One Thing

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