The Bible teaches that true faith in Jesus Christ is essential for salvation. If you’re going to have eternal life, you must have this vital faith connection to Christ. In Acts 16, Paul and Silas were in the prison in Philippi. God sent a great earthquake and all the doors were opened and the chains fell away from the prisoners. The jailer was about to end himself, but Paul stopped him. The jailer then said, “Sirs, what must I do to be saved?” And the simple answer from the apostles was: “Believe in the Lord Jesus and you will be saved…”
Given that faith is essential for salvation, it follows that clarity about the definition of faith is also essential. When it comes to the definition of saving faith, Reformed theology has historically distinguished between three different components: knowledge, assent, and confidence. While these three can be distinguished, they must never be separated. All true saving faith has all three of these components.
The first component of true saving faith is knowledge. With the intellect, one has to know the basics of what is to be believed. One has to comprehend the basics of what the Bible says about God, about ourselves, our sin, our Saviour, the gospel, and so on. Knowledge of the essentials of God’s Word is crucially important.
True faith takes that knowledge and works with it. Faith includes not only knowing the knowledge, having it up there in your head, but also accepting it as being true. This is what we call assent. Let me give you an example of what the difference is between knowledge and assent. I find Islam fascinating. It’s a false religion, but its intricacies are an amazing (and sad) testimony to human creativity. I can read the Qur’an and I know what it says. I may have a basic knowledge of the message of the Qur’an. But that doesn’t make me a Muslim. For one thing, I don’t accept it as being true. Similarly, someone could read the Bible and intellectually know the basic teachings of the Christian faith. Someone could even conceivably go to catechism and go to church each Sunday and have an intellectual interest in Christian doctrine. But they don’t accept it as being true. They may have the knowledge of a Christian, but without accepting it as true, that person isn’t a Christian. He or she doesn’t have saving faith.
According to Richard Muller (Dictionary of Latin and Greek Theological Terms), these first two components of knowledge and assent belong to that human faculty known as the intellect. This is our mind which comprehends and assesses data presented to us. Together knowledge (notitia) and assent (assensus) make up “sure knowledge” (cognitio certa). That term is found in Lord’s Day 7 of our Heidelberg Catechism: “True faith is a sure knowledge…” At first glance, it may appear that the Catechism only describes two components of faith: sure knowledge and firm confidence. However, historically the first component divides into knowledge and assent. There’s a strong hint of that in the Catechism itself when it goes on to say that this knowledge involves accepting as true “all that God has revealed to us in his Word.” “Accepting as true” is the essence of assent.
The third component in saving faith is confidence or trust (fiducia). This element belongs to the human faculty known as the will. The will is that part of a human being that desires. Saving faith must see the person desiring for themselves what the gospel offers in Jesus Christ and then taking hold of him, trusting in him.
The Heidelberg Catechism, in Lord’s Day 7, describes this as a “firm confidence.” A true faith has firm confidence that all the truths of the gospel are not just for other people, but also for me, personally. When I hear a gospel minister say that “God has granted you forgiveness of sins out of mere grace for the sake of Christ’s merits,” I say to myself, “Yes, that’s true for me too!” When I hear a gospel minister say that “God has granted you everlasting righteousness and salvation out of mere grace all because of Christ,” I say, “Amen. That’s my God. That’s my Saviour. This good news is for me!” So true saving faith must include personal appropriation of what the Bible teaches. It’s not enough to know what the Bible says. It’s also not enough to be able to say the Bible is true. You have to go all the way and say that what God offers in the gospel is also for you personally and individually. You must trust in it for yourself.
According to historic Reformed theology then, saving faith consists of knowledge, assent, and confidence. That approach comes straight from Scripture. Think of Hebrews 11:1, “Now faith is the assurance of things hoped for, the conviction of things not seen.” How can we be sure of what we hope for if we don’t know what the Bible teaches? How can we be certain of what we don’t see, if we don’t know anything about what the Bible says and don’t agree that it’s true?
Why does all this matter? There are at least two good reasons.
First, if true faith is essential to salvation, you’d want to make sure you have it. You would want to make sure that you haven’t left out any of those components. After all, there are people who convince themselves that they’re Christians merely because they have some intellectual knowledge of what the Bible teaches.
Second, it’s crucial to notice what’s not included in saving faith. One thing that’s definitely not present in the biblical definition of a true saving faith is good works. Listen to Paul in Romans 3:28, “For we hold that one is justified by faith apart from works of the law.” In that passage “works of the law” are set against “faith.” It’s impossible that Paul meant that faith includes works of the law. Everywhere Scripture teaches about salvation in general and justification in particular, we find that the word “faith” is used in the sense of looking outward to Christ, not looking inward to trust in one’s good works.
Biblical, Reformed theology recognizes how salvation is entirely by grace – undeserved from first to last. That includes our faith. While humans are called to faith, while humans are involved in faith (knowing, assenting, trusting), ultimately faith is something worked in us by the Holy Spirit. Faith is therefore not our contribution to salvation. Ephesians 2:8-9 reminds us: “For by grace you have been saved through faith. And this is not your own doing; it is the gift of God, not a result of works, so that no one may boast.” Praise God for his gift of faith!