What Is Saving Faith?

Central question: If sinners are justified through faith alone, what distinguishes genuine trust in Christ from the mere statement, “I believe”?

Section 01Why Qualify Faith?

I have never been one to qualify words, believing they should stand on their own. Admittedly, when I first heard someone use the term “saving faith,” I was a little put off. Why do we need to qualify faith?

In fact, the specific term “saving faith” is not found in the Bible. So again, I am led to ask: Why do we feel the need to qualify faith? Is there any other kind?

Throughout the history of the church, Christian theologians wrestled with the nature of faith and how sinners are made right with God. During the Reformation, as justification by grace alone, through faith alone, in Christ alone was more carefully articulated, the need to distinguish genuine faith from mere belief became increasingly important.

We see this distinction expressed in the Heidelberg Catechism (1563) as “true faith.” It was developed further by Protestant theologians and then carefully defined in the Westminster Confession of Faith (1646–47) under the heading “Of Saving Faith.”

While the exact term may not appear in the Bible, the concept is firmly established there. Scripture contrasts living faith with forms of belief that do not save. Several foundational Christian doctrines are likewise named by later theological terms even though their substance is taught in Scripture; the doctrine of the Trinity is perhaps the most familiar example.

Section 02At the Heart of the Reformation

The Reformers did not initially seek to separate from the Roman Catholic Church; they sought to reform it. At the center of that effort was a question with eternal consequences: How is a sinner made right with God?

The Roman Catholic Church understood justification as an ongoing process in which grace was imparted through the sacraments and the believer cooperated with that grace through faith and obedience. Baptism, penance, the Eucharist, and obedient participation in the life of the Church were therefore connected to a person’s justification.

The Reformers, however, maintained that Scripture presents justification as God’s gracious declaration that a sinner is righteous—not because of anything the sinner has accomplished, but because of the righteousness of Jesus Christ. The sinner is justified by grace alone, through faith alone, in Christ alone.

But this raised an important question: If sinners are justified through faith alone, can anyone simply say, “I believe,” and then be on his way? The Reformers answered no. Merely professing belief is not necessarily the same as possessing the faith through which a sinner receives Christ. Faith did not need to be supplemented by works before it could save; faith itself had to be properly understood.

Section 03Abraham: One Faith, Two Moments

Both Rome and the Reformers looked to Scripture for the answer, and both found support for their positions in the life of Abraham. Yet they emphasized two different moments in his life.

The Reformers pointed to Paul’s words in Romans 4, quoting Genesis 15:6:

“Abraham believed God, and it was counted to him as righteousness.”

Romans 4:3

Abraham was counted righteous through faith before he was circumcised and apart from any work that could establish his merit before God. Rome, however, could point to James 2 and a much later event:

“Was not Abraham our father justified by works when he offered up his son Isaac on the altar?”

James 2:21

“You see that a person is justified by works and not by faith alone.”

James 2:24

The apparent conflict is unmistakable. Paul says Abraham was justified by faith apart from works. James says Abraham was justified by works and not by faith alone. How can both statements be true?

Roman Catholic theology understood Abraham’s offering of Isaac as part of his growth and continuation in righteousness. The Reformers argued that works follow justification as its necessary fruit but do not contribute to the ground upon which God declares the sinner righteous.

The chronology is important. In Genesis 15, Abraham believed God, and his faith was counted to him as righteousness. In Genesis 17, he received circumcision. Much later, in Genesis 22, Abraham demonstrated the reality of that faith by placing Isaac upon the altar.

Abraham was not counted righteous in Genesis 15 because God foresaw that he would eventually offer Isaac. Nor did offering Isaac complete something lacking in the work of Christ. His obedience revealed and brought to maturity the faith through which he had already been counted righteous.

Paul and James are describing two sides of the same faith. Paul explains how a sinner is justified before God: through faith apart from works. James explains how genuine faith is demonstrated: it produces obedience.

Paul opposes works as the means of justification. James insists upon works as the evidence of faith.

Abraham was justified through faith, and his faith was justified—shown to be genuine—through works.

Section 04The Gate of Paradise

Martin Luther had long understood “the righteousness of God” primarily as the righteousness by which God judges and punishes the unrighteous. Because Luther was painfully conscious of his own sin, those words brought fear rather than comfort.

But as he wrestled with Romans 1:17—“The righteous shall live by faith”—he came to understand God’s righteousness differently. The gospel revealed the righteousness that God graciously provides to the sinner through faith. Luther later recalled that he felt as though he had been born again and had entered paradise through open gates. Paul’s words had become for him “the very gate of paradise.”

Luther discovered that peace with God did not depend upon his religious performance. The sinner is declared righteous by grace, through faith, because of the completed work of Jesus Christ.

Section 05Let Scripture Define Faith

Before turning to definitions developed during the Reformation, we must allow Scripture to speak for itself. Hebrews offers what may be the Bible’s clearest description of faith:

“Now faith is the assurance of things hoped for, the conviction of things not seen.”

Hebrews 11:1

Hebrews is not describing irrational belief in something for which there is no evidence. Nor does faith create reality merely by believing strongly enough. Faith possesses assurance and conviction because its confidence rests upon the character and promises of God.

“And without faith it is impossible to please him, for whoever would draw near to God must believe that he exists and that he rewards those who seek him.”

Hebrews 11:6

The remainder of Hebrews 11 shows that this conviction acts:

• Abel offered.
• Noah constructed the ark.
• Abraham obeyed and went.
• Sarah considered Him faithful who had promised.
• Abraham offered Isaac, believing God could raise him from the dead.
• Moses chose mistreatment with God’s people rather than the pleasures of Egypt.

Hebrews moves from content to conviction to reliance. One must know something about God, believe that what He has revealed is true, and personally approach Him in confidence that He keeps His promises.

Section 06Knowledge, Assent, and Trust

During the Reformation and the period of Protestant theology that followed, theologians commonly described saving faith in terms of three inseparable aspects: knowledge, assent, and trust—sometimes identified by the Latin terms notitia, assensus, and fiducia. These do not replace Hebrews 11:1; they help explain how its assurance and conviction arise.

1. Knowledge — Notitia

Faith must have content. A person cannot believe the gospel without knowing what it declares: that we are sinners under God’s judgment, that Jesus Christ is the Son of God, that He died for our sins, that God raised Him from the dead, and that forgiveness and eternal life are offered through Him. Saving faith is therefore not blind faith. It begins with hearing and understanding the message of Christ.

“How are they to believe in him of whom they have never heard? … So faith comes from hearing, and hearing through the word of Christ.”

Romans 10:14, 17

2. Assent — Assensus

Knowing what the gospel says is not enough. A person must also believe that its claims are true. Assent affirms that Jesus truly is the Son of God, that He truly died and rose again, and that God truly saves sinners through Him. Yet even knowledge and assent are not sufficient:

“You believe that God is one; you do well. Even the demons believe—and shudder!”

James 2:19

3. Trust — Fiducia

Saving faith becomes personal. It does not merely know that Christ saves sinners or agree that the gospel is true. It entrusts the sinner personally to Christ. Trust says more than, “Jesus is a Savior.” It says, “Jesus is my only Savior, and I rest upon Him alone.”

“If you confess with your mouth that Jesus is Lord and believe in your heart that God raised him from the dead, you will be saved.”

Romans 10:9

Paul does not say merely that we must understand the resurrection or agree that it occurred. He speaks of believing “in your heart.” As we have previously seen in Guarding the Heart, Renewing the Mind, the biblical heart encompasses more than emotion. It is the center of the inner person, involving the mind, affections, and will.

Saving faith therefore cannot be confined to the mind. The mind understands the truth, but the heart embraces it. The sinner no longer merely acknowledges facts about Jesus; he entrusts himself to the risen Christ and confesses Him as Lord.

“For with the heart one believes and is justified, and with the mouth one confesses and is saved.”

Romans 10:10

Knowledge hears the gospel. Assent recognizes that the gospel is true. Trust embraces Christ from the heart.

Section 07True Faith and Saving Faith

The Heidelberg Catechism

The Heidelberg Catechism defined true faith as both “sure knowledge” and “wholehearted trust.” The believer knows what God has revealed, accepts His Word as true, and personally trusts that forgiveness of sins, eternal righteousness, and salvation are freely given—not only to others, but “to me also”—solely by grace because of Christ. This faith is not produced by human effort; the Holy Spirit creates it in us through the gospel.

The phrase “to me also” should not be glossed over. True faith is more than affirming a general truth; it is personal. The believer does not merely confess that Christ saves sinners but personally receives and rests upon Christ for his own forgiveness, righteousness, and salvation. This gives theological substance to what many evangelicals call “a personal relationship with Jesus Christ”—not merely an emotional experience, but a life of union and communion with Christ through faith.

The Westminster Confession of Faith

Chapter 14, “Of Saving Faith,” expands this understanding in three directions.

First, saving faith is a work of the Holy Spirit in the heart of the sinner. It ordinarily comes through the ministry of God’s Word and is strengthened through the Word, the sacraments, and prayer.

Second, saving faith receives everything revealed in Scripture as true because God Himself has spoken. It obeys His commands, trembles at His warnings, and embraces His promises. Yet its principal acts are “accepting, receiving, and resting upon Christ alone” for justification, sanctification, and eternal life.

Third, saving faith is not always equally strong. It may be weak or strong; it can be attacked and weakened. Nevertheless, genuine faith perseveres through Christ and grows toward assurance.

The Heidelberg Catechism and Westminster Confession do not compete with Scripture’s definition. They apply it. We know what God has revealed, believe His revelation is true, and entrust ourselves to the God who has spoken—accepting, receiving, and resting upon Christ alone.

Section 08Repentance: The First Expression of Trust

Saving faith is always accompanied by repentance. Repentance is not an additional work that earns salvation or completes something lacking in faith. Repentance and faith describe the sinner’s response to the gospel from two complementary directions: repentance turns away from sin, while faith turns toward and rests upon Christ.

John the Baptist came to prepare the way of the Lord, calling the people to “repent, for the kingdom of heaven is at hand.” His message did not permit repentance to remain an empty profession. He commanded them to “bear fruit in keeping with repentance.” Jesus continued that call and joined it explicitly with faith:

“The time is fulfilled, and the kingdom of God is at hand; repent and believe in the gospel.”

Mark 1:15

Repentance does not mean that the sinner must first conquer sin and make himself worthy of Christ. It means coming to Christ with a changed mind about God, sin, and oneself—with a sincere desire to forsake sin and follow Him.

Repentance begins when we trust God enough to surrender—to lay down our arms, stop fighting against Him, submit to His authority, and entrust our lives to Him. We stop defending our sin and accept that God is right about both our guilt and our need for mercy. This surrender does not earn salvation, nor does it mean that our struggle with sin has ended. It marks a change of allegiance and direction: we no longer claim the right to rule ourselves but confess that Jesus is Lord.

Section 09Laying Down Our Arms

The act of surrender involves a remarkable vulnerability that is difficult to put into words. It requires entrusting yourself completely to another.

As I allow my thoughts to settle, I am taken back to a time in Iraq when several enemy combatants surrendered to us on the battlefield. We placed them on their knees on the desert floor, secured their hands behind their backs, searched them, and kept our weapons trained on them. Because we did not speak the same language, we could not communicate. They had no way of knowing what we intended to do. For all they knew, we might execute them.

They were completely vulnerable. They had surrendered to our authority and entrusted their very lives to our hands. Yet after we secured them, they were transported to the rear, where they were fed and cared for.

This kind of surrender—laying down our arms, abandoning our resistance, and entrusting our lives to another—helps me understand the nature of saving faith. Christ calls us to stop fighting against His authority and entrust ourselves wholly to Him.

Yet there is one important difference. Those combatants did not know our intentions when they surrendered. In contrast, we do know God’s intentions toward those who come to Him through Christ. He has revealed them at the cross. The Judge before whom we surrender is the Savior who gave His life to reconcile His enemies.

We lay down our arms before the One who laid down His life so that we might have life.

Section 10How Can We Be Assured?

If saving faith means receiving and resting upon Christ alone, how can we know that our faith is genuine? How can we be assured that we have truly been saved?

Our assurance must begin where our faith began: not with ourselves, but with Jesus Christ. We are not saved because our faith is exceptionally strong, our repentance is perfect, or our works are sufficient. We are saved because Christ is sufficient. The strength of our assurance rests first upon the character, promises, and completed work of the One in whom we have placed our trust.

“Everyone who calls on the name of the Lord will be saved.”

Romans 10:13

Yet Scripture also teaches that genuine faith does not remain barren:

“Faith by itself, if it does not have works, is dead.”

James 2:17

Works do not make faith saving, but saving faith produces works. They are not the basis of our justification but evidence that the Holy Spirit is at work within us.

“Work out your own salvation with fear and trembling, for it is God who works in you, both to will and to work for his good pleasure.”

Philippians 2:12–13

As we considered more fully in The Will and Sanctification, Paul holds our obedience and God’s transforming work together. We are not commanded to earn our salvation. God is already at work within us, providing both the desire and the power to respond in obedience.

Salvation does not leave the mind, heart, and will unchanged. Through sanctification, the Holy Spirit renews our minds by truth, develops new desires within our hearts, and increasingly brings our wills into obedience.

This transformation is neither immediate nor complete in this life. Christians continue to struggle and sometimes fall grievously. The evidence of saving faith is not sinless perfection but a changed direction: continuing reliance upon Christ, hatred of sin, repentance, and a growing desire to obey God.

Assurance does not mean looking back at a single profession of faith while presently having no concern for Christ. Saving faith continues to return to Him. The same Christ upon whom we first relied for justification remains the One upon whom we rely throughout sanctification. From beginning to end, our hope remains Christ and Christ alone.

Assurance therefore has both a foundation and confirming evidence. Its foundation is the completed work and trustworthy promise of Christ. Its confirming evidence is the living faith and continuing transformation produced by the Holy Spirit.

Biblical assurance is not presumption. God intends believers to know that they possess eternal life, and He grounds that assurance in His written Word:

“I write these things to you who believe in the name of the Son of God, that you may know that you have eternal life.” —1 John 5:13

Historical Sources

1. Heidelberg Catechism, Question 21: “What is true faith?”
2. Westminster Confession of Faith, Chapter 14: “Of Saving Faith”
3. Martin Luther, Preface to the Complete Edition of Luther’s Latin Writings (1545)