This review on the book Commentary on the Heidelberg Catechism (2025) was written by Tony Mankodi. The reviewer received a B. Tech (Hons.) degree in Mech. Engg. in 1976, from the Indian Institute of Technology, Kharagpur, and worked in senior management roles in projects and design engineering until his retirement in 2017. He served as a pastor in Mumbai, India, from 2000 and later also provided oversight of churches until his retirement in 2017.

Introduction: A Forgotten Treasure of Reformed Faith

Zacharias Ursinus wrote his Commentary on the Heidelberg Catechism almost 500 years ago, during a time when the Church was going through big changes. Christians were returning to the Bible, and important truths that had been neglected were being rediscovered. Ursinus’ work became a clear and faithful explanation of biblical teaching, especially from a Reformed point of view. 

What’s surprising is that even though this book has been translated into English, it’s still not widely read today. The Heidelberg Catechism itself—which was once used to teach and train people in the faith—is also not as well known anymore. This isn’t just because people read less today. It shows a deeper issue: many churches have drifted away from the strong, Bible-based teaching that shaped the Reformation.

When we let go of resources like this one, we miss out on the wisdom and comfort they offer. Ursinus’ work isn’t just full of deep theology—it also feeds the soul. In a time when spiritual life often feels shallow and rushed, this book calls us back to a kind of faith that is thoughtful, grounded in Scripture, and rich in comfort. 

The Two Introductions: “Prolegomena” and “Special Prolegomena” 

Right from the beginning, Ursinus shows that he’s not just a teacher—he’s also a careful and organized thinker. Before jumping into the main part of his commentary, he begins with two introductory sections. These are titled Prolegomena and Special Prolegomena. Those might sound like intimidating words, but they’re really just two opening chapters that lay the foundation for everything that follows. 

The First Introduction: What Christian Teaching Is and Why It Matters

In the first section, Ursinus talks about doctrine—which just means the teachings of the Christian faith. He explains what doctrine is, why it matters, and how it should be taught in the church. For Ursinus, good teaching must come from the Bible and focus on two main things: God’s Law and the Good News (or Gospel) of Jesus Christ.

He says that God’s truth, when rightly taught, brings salvation to God’s people and gives glory to God Himself. He also reminds us that the Church needs to stay set apart from the world in order to protect and pass on this truth. Without sound teaching, both the Church and the believer lose their way.

Ursinus also talks about how the Law and the Gospel work together. The Law shows us our need for grace by revealing our sin. The Gospel shows us God’s grace by pointing us to Christ. Both are found throughout the Bible, and both are essential for understanding the Christian life.

To show that Christian teaching is true, Ursinus uses several kinds of evidence—such as fulfilled prophecies, miracles, and the unity of the Bible’s message. He ends this part by naming three main ways to grow in the faith: being taught through questions and answers (like a catechism), studying topics in more depth (like in theology classes), and reading the Bible regularly. The last one, he says, is the most important. 

The Second Introduction: Why We Teach the Faith to Others

In the second introductory section, Ursinus turns his focus to catechism itself—that is, the practice of teaching the basics of the faith, especially to children and new believers. This kind of teaching, he says, has been part of the Church since Bible times.

He describes two groups of people who need this kind of training: adults who are new to the faith, and children who are growing up in Christian homes. For both, learning the basics—especially the Ten Commandments and the Apostles’ Creed—is essential. These two summaries of the faith teach us who God is, what He expects, and how He saves. 

Ursinus argues that this kind of instruction isn’t optional—it’s necessary. It helps people come to faith, protects the Church from false teaching, and brings deep comfort and joy by helping believers know and love God more. 

The Main Theme: Real Comfort Through the Bible

At its heart, Ursinus’ Commentary is all about comfort—real, lasting comfort that comes from knowing and trusting God. That’s actually the first thing the Heidelberg Catechism talks about. The very first question asks, “What is your only comfort in life and in death?” That theme—Christian comfort—runs through the entire book.

Ursinus believes that true comfort can only come from the Bible, when it is rightly understood and deeply believed. His commentary is meant to help people do exactly that: understand the Scriptures clearly and trust in the promises of God. He teaches the Bible in a way that helps readers not only grow in knowledge, but also find peace and strength in their faith. 

He had a high view of Scripture. He saw it not just as a source of truth, but as a source of life—especially during difficult times. That’s why he worked so hard to explain the Bible carefully and clearly. He wanted readers to know that the comfort God offers isn’t shallow or temporary; it’s deep, lasting, and meant to carry us through every part of life, including our hardest moments.

This isn’t a quick or casual kind of comfort—it’s the kind that comes from knowing who God is, what He has done through Christ, and how the Holy Spirit works in us. Ursinus believed that if people really understood these things, they would find a joy and confidence that nothing else can give. 

How the Book Is Organized: Teaching, Defending, and Caring for the Soul

Ursinus follows the Heidelberg Catechism step by step in his commentary, going through each section called a “Lord’s Day.” This setup helped churches back then reflect on one part of the Catechism each week. That way, people could slowly grow in their understanding over time.

Right from the start—with the opening question about comfort—Ursinus keeps a warm and caring tone. He doesn’t just write like a scholar; he writes like a pastor who wants people to understand and trust God more. His goal is to help readers grow in their faith, find encouragement, and learn how to live as Christians in everyday life.

The way the book is written also helps people learn. Each part is laid out as a question followed by an answer. This method, called catechism, was used a lot during the Reformation. It’s helpful because it teaches big truths in a simple format that’s easy to remember and talk about. 

Ursinus doesn’t just explain the Catechism—he also defends it. When false teachings come up, he responds with Scripture. He wants people to know not just what the Bible says, but how to recognize and resist ideas that go against it. He explains everything clearly and carefully, so readers feel both informed and protected.

He covers the big parts of the Christian faith: what we believe (like the Apostles’ Creed), how we live (like the Ten Commandments), how we pray (like the Lord’s Prayer), and how we receive God’s grace (like the sacraments of baptism and the Lord’s Supper). But what makes his writing stand out is how deeply he connects all of these things to God’s Word, how clearly he explains them, and how much he cares for his readers’ spiritual growth.

Going Deeper: Big Truths Made Clear 

Ursinus doesn’t just repeat what the Heidelberg Catechism says—he helps us go deeper. He shows how the truths in the Catechism connect with many parts of the Bible and how they affect real life. His goal isn’t just to teach facts, but to help readers think deeply about God’s truth and grow in their relationship with Him.

He uses a three-part structure to explain the Christian life: 

• Guilt (our sin) – Questions & Answers 3–11 
• Grace (God’s rescue through Jesus) – Questions & Answers 12–85 
• Gratitude (how we live in response) – Questions & Answers 86–129 

This pattern helps us understand the story of salvation: We are lost in sin, rescued by Jesus, and then called to live in thankful obedience.

Ursinus also connects this structure to the three Persons of the Trinity: 

• God the Father, our Creator – Q&A 12–23
• God the Son, our Redeemer – Q&A 24–85
• God the Holy Spirit, who makes us holy – Q&A 86–129

He doesn’t just explain doctrines in isolation—he shows how all these teachings fit together and reveal the beauty of who God is.

He also lays out the main areas of Christian living: 

• The Ten Commandments – God’s will for our lives
• The Apostles’ Creed – What Christians believe
• The Sacraments – How God strengthens our faith
• The Lord’s Prayer – How we talk with God 

Everything is rooted in the Bible. Ursinus writes clearly so that readers can understand and see how every part of faith is connected. His writing helps people not only believe the right things but also live them out with joy and confidence. 

Law and Gospel: Why Both Are Important 

One of the most important things Ursinus teaches is the difference between the Law and the Gospel. Sadly, this difference is often overlooked today, but it’s a big part of how we understand the Bible and the Christian life. 

• The Law shows us what God expects from us. It tells us how we should live and makes clear that we fall short—it shows us our sin.
• The Gospel is the good news that Jesus saves sinners. It tells us about God’s grace, forgiveness, and the gift of eternal life through Jesus. 

Ursinus is careful to keep the two separate but connected. The Law tells us the truth about our condition, and the Gospel tells us how God has rescued us through Christ. If we mix them up, we can fall into two dangers: 

• Moralism – trying to earn God’s love by keeping rules.
• Antinomianism – ignoring God’s commands because we think grace means anything goes.

Ursinus helps us stay balanced. He shows that we need both the Law and the Gospel to understand our need for a Savior and to live a life that honors God. His teaching protects us from confusion and helps us grow in faith and obedience without fear or pride. 

Finding Assurance: How We Can Know We’re Saved 

Another strength of Ursinus’ teaching is how he explains assurance—that is, how we can be sure we truly belong to Christ. He wisely shows that assurance has two parts: 

• Objective assurance comes from outside of us. It’s based on God’s promises in the Bible and the finished work of Jesus on the cross. These truths don’t change, even when our feelings do.
• Subjective assurance is how we feel or experience that truth inside us. It grows through the work of the Holy Spirit and through seeing the fruits of faith in our lives—like love, trust in God, and a desire to obey Him. 

Some people struggle with doubt, especially when they look at their own weaknesses. Ursinus offers comfort by reminding us that our confidence doesn’t rest on how strong our faith feels, but on how strong our Savior is.

At the same time, he encourages us to look for signs of God’s grace in our lives. Are we growing in repentance? Are we beginning to love God and others more? These aren’t the cause of our salvation, but they are helpful signs that God is at work in us. 

This balance gives peace to troubled hearts and helps Christians stay grounded in God’s truth without depending too much on changing emotions. 

God’s Grace: How It Comes to Us and What It Produces 

Ursinus also explains something very helpful about the way God works in our lives. He makes a clear difference between two important ideas: 

• The means of grace are the ways God gives us His grace. These include the Bible (God’s Word), the sacraments (Baptism and the Lord’s Supper), and prayer. These are God’s gifts to help our faith grow. 
• The evidences of grace are the results of grace in our lives—things like repentance, love, obedience, and trust in God. These are the fruits that show God’s work in us. 

This is important because some people confuse the two. For example, they might think they earn God’s favor by being good or by doing religious things. But Ursinus reminds us that grace comes first. God gives it freely. Our good works come afterward, as a response to His love—not as a way to earn it. 

By keeping this order clear—grace first, works second—Ursinus helps us avoid two major errors: 

• Legalism: trying to earn God’s acceptance through rules and performance.
• Sacramentalism: thinking the sacraments work automatically without real faith. 

Instead, he points us to a life shaped by grace—receiving it through the means God has given, and then showing it through a life of thankful obedience.

Polemical Clarity: Standing Firm in the Truth 

Ursinus doesn’t shy away from addressing errors in teaching. He wants to make sure we understand and hold to the truth, especially when it’s challenged. But his approach is calm and respectful. He doesn’t attack or argue in a harsh way—he simply explains why the Bible teaches what it does and why some other ideas don’t line up with Scripture. 

For example: 

• Justification by faith alone is one of the most important doctrines. Ursinus clearly explains this in Q&A 59–64, showing from the Bible (Romans 3–4) that we are made right with God not by anything we do, but only through faith in Jesus.
• He also addresses the issue of images in worship (Q&A 96–98), explaining why the Bible forbids the use of idols or images in the church. 
• Another key point is his clear rejection of the Mass as a meritorious sacrifice (Q&A 80). He firmly calls it “accursed idolatry,” standing against the idea that the Mass can somehow offer grace or forgiveness through the actions of the priest. 

These are bold statements, but Ursinus makes them with a goal: to teach the truth of Scripture clearly and carefully. He upholds the teachings of the Reformation, and he uses biblical arguments to do so. His tone is strong but always rooted in the authority of the Bible, not in personal attack or emotional argument. 

Ongoing Relevance: A Guide for Today 

Though the Commentary on the Heidelberg Catechism was written centuries ago, it’s still relevant for us today. Ursinus wrote it to bring unity among different Protestant groups, particularly in the Palatinate region. The Heidelberg Catechism, along with the Belgic Confession and the Canons of Dort, make up what is known as the Three Forms of Unity— the foundational documents for Reformed theology. 

But even today, there are still disagreements among churches about important topics like Baptism. Some still believe in Baptismal Regeneration, the idea that baptism actually saves. This is something the Reformed tradition rejects, and Ursinus helps us understand why. 

His work helps pastors and congregations navigate these differences with clarity, without causing unnecessary division. By reading Ursinus, we gain a clear understanding of biblical truth that can guide us through disagreements in the Church while preserving unity in essential matters. 

Throughout the Commentary, Ursinus engages with the teaching of the Roman Catholic Church. He addresses issues like the veneration of Mary, the Mass, and the role of mediators between God and humans. He does this respectfully but firmly, reaffirming Reformation principles like Sola Fide (faith alone), Sola Scriptura (Scripture alone), Solus Christus (Christ alone), and the priesthood of all believers. 

While Ursinus critiques these teachings, his main goal is to show how the Bible points to Christ and His finished work as the only source of salvation. He does this in a way that is clear and faithful to the Word of God, while also calling the Church to return to Scripture as the ultimate authority.

Final Reflections: Teaching with Clarity, Reading with Care: Ursinus for Today’s Shepherds and Students 

Ursinus’ Commentary on the Heidelberg Catechism isn’t the easiest book to read, but it’s well worth the effort. It requires careful and thoughtful reading, but as you work through it, you’ll find that it is packed with rich, biblical teaching. The full text spans about 672 pages, and though it’s a long read, the reward is great.

This isn’t a book to rush through though. It’s a book to study slowly and to reflect on carefully. The way it’s written makes it easier to stick with it, especially if you have a well-bound edition with clear formatting. This helps keep your focus on the theology and ensures you don’t get lost in the text. 

Teachers could explore the contents further by asking questions such as: 

• What does Ursinus’ method teach us about theological catechesis in the face of doctrinal confusion? 
• How does his polemic method inform contemporary pastoral responses to theological relativism, or ecclesiastical drift? 

So even though Ursinus was writing in the 16th century, what he presented as both polemical (written to defend doctrine and refute error) and pastoral (caring for the church’s well-being) still speaks clearly today—as it retains its pedagogical (teaching) and ecclesiological (church) vitality, meaning, to put it quite simply, it remains just as important for teaching and for the life of the church now in the 21st century as it was back then. 

Conclusion: Rediscovering Theological Depth 

In a world where many are drawn to quick fixes and shallow spirituality, Ursinus’ Commentary calls us back to deep, thoughtful engagement with God’s Word. It’s a theologically rich and pastorally wise book that helps us understand the foundations of the Christian faith. Anyone reading this will know that Ursinus in effect affirms that sound theology leads to piety. Through this Commentary, we’re invited to rediscover the joy of the five solas of the Reformation: sola gratia, sola fide, solus Christus, sola Scriptura, and soli Deo gloria. These truths are as relevant today as they were in the 16th century, and they continue to point us to the grace and truth of our Savior, Jesus Christ. 

- Tony Mankodi

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