What is theology? We might say that at its most basic understanding, theology is the study of God and everything else in its relation to God. In other words, we might describe theology by what it studies (its object of inquiry) and how it studies that object.
Theology first and primarily studies God. It is no wonder that theology is called theology (θεος; theos—God), as the theological titan, Thomas Aquinas, says, “The object of the science is that of which it principally treats. But in this science, the treatment is mainly about God; for it is called theology, as treating of God. Therefore God is the object of this science.”Theology studies God in two aspects: in himself (in his trinitarian nature, essence, and being [referred to as “theology proper”]) and in his external works (his acts in the created domain).
Theology’s secondary object of study is everything that is not God, that is, that which is created. In this vein of theology, we study things such as the nature of creatures, the end(s) (telos) of creatures, the relation between God and creatures, and the domain of creation, that is, its history and setting. This secondary part of theology is not unrelated to the first part. Because God is and God acts and so gives created things their existence, in studying creation, we are studying God’sworks; that is, we are still studying God in the aspect of his external works as we study creation. This is not to say that the Creator and creature are blended and identical. No, we mean to say that when we study a created thing, we study an object of God’s work, which requires thought about God.
Theology studies God and everything else in a particular manner and from a unique source. First, when theology studies created things, it should do so by studying them in relation to God? Why is this so? If we want to study created things as they really are, we must study them as createdthings—that which exists only because God created it. To study creatures as they are is to study them as being who have their existence from God. When we study creation, therefore, we don’t ever stop talking about God. Indeed, we should talk about creation by talking about Godas its beginning or end.Second, theology can be practiced only because (1) God knows himself and all things and (2) because God imparts a measure of his knowledge to us through (a) general revelation in creation (e.g., Ps 19:1; Rom 1:19–21), (b) the missions of the Son and the Holy Spirit (e.g., John 1:18; 1 Cor 2:10–16), and (c) Holy Scripture—God’s written word. Theology’s sources (of knowledge) are thus God, his works, and the Bible. We know only because God exists, God reveals, and he has given us his God-breathed book, Scripture. The Bible is the written word of God. Therefore, Holy Scripture directs theological thought.
Finally, for theology to be practiced appropriately, it must have a certain goal. Theology’s end is to know and love God.If theology ends without either of those two, the theology is not theological. When theology does not meet its goal of both knowing and loving God, it truly is not being what it is—an instrument that aids creatures in what they were created to do.
St. Thomas Aquinas, Summa Theologiae, Prima Pars I, 1–49, Latin/English Edition of the Works of St. Thomas Aquinas 13, trans. Fr. Laurence Shapcote, eds. John Mortensen and Enrique Alarcón (Lander, WY: The Aquinas Institute, 2012), Ia.1.7 sed contra.
John Webster, “Non ex aequo. God’s Relation to Creatures,” in God Without Measure, 1:117.
Aquinas, STIa.1.3 ad. 1.
John Webster, “Biblical Reasoning,” in The Domain of the Word: Scripture and Theological Reason(London: Bloomsbury T&T Clark, 2012), 1:117–118, 121, 124, 132.