What Is Reformed Theology? (Part 2)

by on September 1, 2025 | Comment

Trinitarian

Unfortunately, when most people think of Reformed theology, they think of the doctrine of predestination. The reasons for this have more to do with the critics of Reformed theology than with what the Reformed themselves confess. Indeed, one of the great weaknesses of the modern Reformed renaissance is that it tends to redefine Reformed theology almost entirely in terms of the doctrine of divine sovereignty.

It would be closer to the truth to say that the doctrine of God is at the headwaters of Reformed theology as it is for every orthodox Christian tradition. After all, the Apostles’ Creed begins with the doctrine of God: “I believe in God the Father Almighty, maker of heaven and earth.”1 We say the same thing in the Nicene Creed.2 The Reformed doctrine of divine sovereignty is an ancient, ecumenical doctrine. Though people today refer to the doctrine of divine sovereignty as Calvinism, that is a misnomer. The ancient fathers routinely and freely spoke of the doctrine of election centuries before St Augustine defended it against the heretic Pelagius in the late fourth and early fifth centuries.

When we explain our doctrine of God, we start where the ancient church began: with the doctrine of the Trinity—that is, the teaching of holy Scripture that God is one in three persons. In Belgic Confession (art. 8) the Reformed churches confess:

According to this truth and this Word of God, we believe in one only God, who is one single essence, in which are three persons, really, truly, and eternally distinct, according to their incommunicable properties; namely, the Father, and the Son, and the Holy Spirit. The Father is the cause, origin, and beginning of all things, visible and invisible; the Son is the Word, Wisdom, and Image of the Father; the Holy Ghost is the eternal Power and Might, proceeding from the Father and the Son.3

In a Reformed church, when the minister begins a Lord’s Day worship service with the invocation from Psalm 124:8, “Our help is in the name of the LORD, who made heaven and earth” (ESV), the God who calls us to worship is the God who is one in three persons. The God who inspired the Psalmist to write those words is Father, Son, and Holy Spirit.

In Reformed theology, the doctrine of the Trinity is not window dressing for a generic doctrine God. We do not get to the Trinity after we consider the divine attributes. Rather, we start with the Trinity on the conviction that, as we say in the Belgic, we know the Trinity from “from the testimonies of Holy Scripture” and “from the operations” of the Trinity “in ourselves.”4 The doctrine of the Trinity is revealed in so many places in the Old Testament that we have to choose them “with discretion and judgment.”5

What was implicit in the Hebrew Scriptures becomes completely clear in the New Testament. The Father and the Spirit were present at the baptism of Jesus (Mark 1:10, 11). Our Lord Jesus commanded his church to baptize in the name of the Triune God (Matt 28:18–20) and the Apostle Paul pronounced a trinitarian benediction upon the Corinthian congregation (2 Cor 13:14).

Though we know that all the works of the Trinity relative to our creation and redemption are the works of the whole Trinity, there are, nevertheless, also distinctions to be made. After all, the Father, the Son, and the Holy Spirit are personally distinct. The Father is unbegotten. The Son is eternally begotten, and the Spirit proceeds eternally from the Father and the Son. So, when we explain the faith we do so under Trinitarian headings. For example, in the Heidelberg Catechism (1563), we speak to the doctrines of creation and providence under the heading of the Father. We speak of the accomplishment of redemption under the heading of the Son, and we speak of the application of redemption under the heading of the Holy Spirit. Where much of evangelical theology tends to divorce the work of the Spirit from the church, the Reformed churches think about the church as the place where the Holy Spirit has ordained to work. So, in that way, the Reformed give a great deal of attention to the person and work of the Spirit.

Augustinian

One of the chief works of the Spirit is to raise those who are spiritually dead to new life and to true faith and, through faith, to unite them to Christ. This is necessary because, as Paul says, by nature, after the fall, we are all born dead in sin (Eph 2:1–4). It is because of Paul’s “but God” (v. 4) that we have any hope. We have been saved by God’s marvelous undeserved favor.

The theologian who, more than anyone else in church history, helped us to recover and understand these truths was St Augustine of Hippo (AD 354–430). From about AD 380 until his death he did theological and ecclesiastical battle with a heretic named Pelagius, a British monk, who denied the biblical doctrine that sin entails spiritual death (Gen 2:17; Rom 6:23). He taught that Adam set a bad example and Jesus set a good one and, if we put our minds to it, each of us has it within him to choose to imitate Jesus. The Reformed churches, however, sided with Augustine and St Paul. The first man, Adam, brought death by his disobedience but the Last Man, Christ, brought life, righteousness, and salvation (Rom 5:12–21; 1 Cor 15:45). The Reformed churches followed Augustine (and the Augustinians through the Middle Ages) on the freedom and sovereignty of grace for helpless sinners.

Catholic

The Ancient Church was challenged not only by Pelagius but before him by a number of heretical movements that attacked the biblical doctrine of the person of Christ. The ecumenical church responded by confessing that Jesus of Nazareth, the Christ, is true God and true man, one person. The Eutychians confused his two natures by saying that he really had one nature and that the deity more or less wiped out the humanity. The Nestorians responded by trying to separate the two natures into two persons. Before them, one set of modalist heretics tried to make Jesus into a mere power of God and another set of modalists tried to make Jesus into merely one of three faces of God. Still other heretics taught that Jesus was a man who was adopted by God.

The Reformed churches stand with the Nicene Creed (AD 325; 381), the Definition of Chalcedon (AD 451), and the Athanasian Creed. We say that God the Son is “true God of true God, begotten not made, being of one substance with the Father; by whom all things were made; who, for us men and for our salvation, came down from heaven, and was incarnate by the Holy Spirit of the Virgin Mary, and was made man.”6 He is, as we say in the Definition of Chalcedon, “perfect in deity and also perfect in humanity; truly God and truly man, of a rational soul and body; consubstantial with the Father according to the deity, and consubstantial with us according to the humanity; in all things like unto us, without sin; begotten before all ages of the Father according to the deity.”7 The properties, we say, of the humanity remain unchanged and the properties of the deity remain unchanged in the incarnation and yet Jesus Christ is one person.

According to the Reformed, that Jesus is consubstantial with us, as we all say in the Definition of Chalcedon, means that what makes us human is what makes him human. He is our truly human, glorified, Mediator before the Father in the holy of holies (1 Tim 2:5; Heb 9:3). He understands us (Heb 4:15). He hears and answers our prayers. He makes them known to the Father. We have no need of earthly priests, nor do we call on saints or even the blessed virgin to hear our prayers. Jesus is enough.

Protestant

As the ancient church battled the Gnostics, Marcionites, and even their Jewish critics, they so stressed the unity of Scripture that they came to describe everything in the Bible as law. St Augustine, however, in his battle with Pelagius, opened a little window on this problem that, in the Reformation, Luther, Calvin, and their successors, pushed wide open: The Bible is unified but there are two kinds of words in Scripture, law and gospel. They are found throughout the Scriptures, in both the Old and New Testaments. Paul explained it this way in 2 Corinthians 3:6: “The letter” (i.e. the law) kills, “but the Spirit” (i.e., the gospel) gives life. As Augustine suggested and Luther explained, these two words do different things to sinners. The law condemns and the gospel proclaims good news.

The law says:

  • “Do this and live” (Luke 10:28)
  • “It is not the hearers of the law but the doers of the law who will be justified” (Rom 2:13)
  • “You shall keep My statutes and my judgments, by which a man shall live if he does them; I am Yahweh” (Lev 18:5)
  • “Cursed is everyone who does not continue to do everything written in the book of the law” (Deut 26:27; Gal 3:10)8

The law never changes but because of our depravity, we are incapable of doing what the law requires. The Spirit uses God’s law, which is like a strict teacher, to drive us to Christ (Gal 3:24).

The gospel says:

  • “He shall strike you on the head and you shall strike his heel” (Gen 3:15b)
  • “I will be a God to you and to your seed after you” (Gen 17:7)
  • “I am Yahweh your God, who brought you out of the land of Egypt, out of the house of slavery” (Ex 20:2)
  • “For God so loved the world that he gave his only begotten Son so that whosoever believes in him should not perish but have everlasting life” (John 3:16)
  • “Come to me all who labor and are burdened and I will give you rest” (Matt 11:28)9

These are all divine promises to needy sinners about what God was to do in Christ, and in the New Testament about what God the Son incarnate has done and does for sinners: He saves them freely, by grace alone, through faith alone.

The Reformed churches embrace the distinction between law and gospel as basic to their reading of Scripture. As Luther said, “Whoever knows well how to distinguish the Gospel from the Law should give thanks to God and know that he is a real theologian.”10 Calvin and his orthodox successors followed Luther on this point.11 For example, Theodore Beza (1519–1605) wrote in 1559:

We divide this Word into two principal parts or kinds: the one is called the “Law,” the other the “Gospel.” For all the rest can be gathered under the one or other of these two headings. . . . We must pay great attention to these things. For, with good reason, we can say that ignorance of this distinction between Law and Gospel is one of the principal sources of the abuses which corrupted and still corrupt Christianity.12

In his commentary on Galatians, William Perkins (1558–1602) echoed Luther:

When Paul says, “The law is not of faith,” he sets down the main difference between the law and the gospel. The law promises life to him that performs perfect obedience, and that for his works. The gospel promises life to him that does nothing in the cause of his salvation, but only believes in Christ. And it promises salvation to him that believes, yet not for his faith, or for any works else, but for the merit of Christ. The law then requires doing to salvation; and the gospel, believing, and nothing else.13

This distinction did not mean for the Reformation churches that God’s moral law (e.g., the Ten Commandments; Matthew 22:37–40) has nothing to say to the Christian or even to society. All the Reformation churches affirm the abiding validity of moral law as the norm of the Christian life. What it does mean is that no one who is united to Christ by the Spirit, through faith, who has been justified by grace alone, through faith alone is under the condemnation of the law. Paul says, “There is therefore now no condemnation for those who are in Christ Jesus” (Rom 8:1). We who are in Christ are “not under law, but under grace” (Rom 6:4).

Next time: What the Reformation faith says about salvation, the church, and the sacraments.

notes

  1. Philip Schaff, The Creeds of Christendom, with a History and Critical Notes: The Greek and Latin Creeds, with Translations. Vol. 2 (Harper & Brothers, 1890), 45.
  2. Schaff, Creeds, vol. 2, 57.
  3. Schaff, Creeds, vol. 3, 390. The translation published here is slightly revised according to the French and Latin texts.
  4. Schaff, Creeds, vol. 3, 391. Translation revised according to the French and Latin texts.
  5. Schaff, Creeds, 3, 391.
  6. Schaff, Creeds, vol. 2, 59.
  7. Schaff, Creeds, vol. 2, 63. Translation revised for archaic language.
  8. My translations.
  9. My translations.
  10. Martin Luther, Lectures on Galatians, 1535, Chapters 1-4, ed. Jaroslav Jan Pelikan, Hilton C. Oswald, and Helmut T. Lehmann, Luther’s Works vol. 26 (Concordia Publishing House, 1999), 115. For more on this distinction see R.Scott Clark, “Letter and Spirit: Law and Gospel in Reformed Preaching,” in R. Scott Clark, ed. Covenant, Justification and Pastoral Ministry: Essays by the Faculty of Westminster Seminary California (P&R Publishing, 2006), 331–63; R. Scott Clark, “Law and Gospel in Early Reformed Orthodoxy: Hermeneutical Conservatism in Olevianus’ Commentary on Romans,” in Jordan J. Ballor, David S. Sytsma and Jason Zuidema editors, Church and School in Early Modern Protestantism: Studies in Honor of Richard A. Muller on the Maturation of a Theological Tradition (Brill, 2013).
  11. See e.g., Institutes of the Christian Religion, 2.5.12; 2.9.4 in any edition. See also his commentary on Second Corinthians 3:6, Institutes, 2.15.12, 3.11.14, 18, and many other places. See also John Calvin, Tracts Relating to the Reformation, vol. 3, trans. Hendry Beveridge (Calvin Translation Society, 1851), 156; R. Scott Clark, “‘Subtle Sacramentarian’ or Son? John Calvin’s Relationship to Martin Luther” Southern Baptist Journal of Theology 21.4 (2018): 35–60.
  12. Theodore Beza, Beza, The Christian Faith, trans. James Clark (Focus Christian Ministries Trust, 1992), 43.
  13. William Perkins, The Works of William Perkins, ed. Paul M. Smalley, Joel R. Beeke, and Derek W. H. Thomas, vol. 2 (Reformation Heritage Books, 2015), 177.

Read the whole series so far.

©R. Scott Clark. All Rights Reserved.

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  • R. Scott Clark
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    R.Scott Clark is the President of the Heidelberg Reformation Association, the author and editor of, and contributor to several books and the author of many articles. He has taught church history and historical theology since 1997 at Westminster Seminary California. He has also taught at Wheaton College, Reformed Theological Seminary, and Concordia University. He has hosted the Heidelblog since 2007.

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