“Believe on the Lord Jesus Christ and you will be saved” (Acts 16:31). This is one of the most well-known verses in all of Scripture—and for good reason. It is, after all, a clear declaration of how one is saved.
I have taught the new members class (Vision and Values) at our church a number of times. There is always a section where I explicitly teach through the Gospel. One of the ways to present the Gospel is to talk about it thematically in four separate themes (God, Sin, Jesus, Salvation). You speak about the person, nature, and character of God—that He is holy, just, good, and right. In light of His holy character, you then talk about the offense of sin—how it separates us from God. And if God is just, He must deal rightly and justly with the problem of our sin. So the way He deals with sin, according to the Scriptures, is through the death and resurrection of Jesus Christ—His holy, perfect Son. Jesus took on flesh, living a holy life that was well-pleasing to the Father. He lived the life we could not live. He then took the punishment of sin on our behalf, substituting Himself in our place. He gets death; we get righteousness. This, of course, is the way salvation becomes a reality. A person is saved from the judicial wrath God—eternal death.
After teaching this, I always quote Acts 16:31—saying, in light of this Gospel, you must believe in Jesus to receive its benefits. No one debates. I then pose the question—now if you say you believe in Jesus, what exactly does that mean? In other words, what do you mean when you say, “I believe in Jesus,” and how is it that this actually saves you? I have learned most do not think about this question. In fact, to say that you “believe in Jesus” is actually to say one of the most ambiguous statements in the Christian faith.
For instance, are you believing (i.e., assenting) to historical facts? That is, are you simply assenting to the reality that 2,000 years ago God became flesh, lived a perfect life, died on a cross, rose again, and will come back to judge the living and the dead?
Are you believing the propositional statement that God desires to save sinners?
Are you believing that God has made a way for salvation?
Are you believing the Bible is the very Word of God?
Are you believing the Church is the body and bride of Christ?
Most pointedly, are you believing you’re a sinner by your very nature, defined by a hostile state toward your Creator?
Most no one in the class ever denies these statements. They’re all believing them, and they’re all believing them to be true and accurate. The problem, however, as I usually inform the class, is that believing every one of those statements doesn’t actually constitute salvation. And the reason for that is because every single one of those statements are nothing more than a set of intellectual facts. In truth, James 2:19 speaks rather candidly to this point— “You believe that God is one. You do well; the demons also believe, and shudder.” Truthfully, the demons have far better theology than most of us will have on this side of heaven, and at least their theology causes them to tremble. They understand and believe all the above statements at a far deeper, indeed, realistic level. Of course, as in the case of the demons, believing those things does not save.
So what, then, is it that we can say actually saves a person? What does it mean to believe in Jesus, as Acts 16:31 says, in a manner that is truly saving? Well as we saw in James 2:19, we can begin by understanding what believing in Jesus is not. It is not merely believing certain things about Him. For the demons, and even Satan himself, know many true things about Jesus.
But more to the point, the answer is bound up with the definition of the term “faith.” Faith is what saves a person. But faith, as we’ve drawn from James 2:19, is more than merely knowing a set of facts and agreeing that they are true. At its core, when everything is stripped away, built into the very root definition of the term “faith” is nothing less than the simple idea of trust. Faith must go beyond knowledge, to a real, living trust in that knowledge. (Which, by the way, is way right knowledge is so important. You can have all the trust in the world, but if it’s based on a wrong set of facts, no amount of trust (i.e., faith) will save you).
We see this idea clearly laid out in Hebrews 11, which is commonly referred to as the Hall of Faith. The chapter is filled with a great cloud of witnesses demonstrating what saving faith (i.e., saving trust) looks like. They were models, indeed, heroes—prime exemplars of what it meant to trust in the living God. What’s fascinating about these examples, though, is as you work through the various people and their circumstances, what we discover is they were all trusting something different. But having said that, we also discover they were each trusting in a single underlying reality. When you strip away the content of what they were trusting in—you actually discover they were all trusting the same thing. And what they were trusting, in every single case, was a particular promise of God. This, when all is said and done, is the core of the Christian life.
When we say we’re believing in Jesus in a saving way (Acts 16:31) we’re actually saying nothing less than we are trusting in Jesus. But this should never remain ambiguous. According to saving faith, all throughout the Scripture (and clearly illustrated in Hebrews 11), trusting in God (or believing in God) always means trusting in a particular promise of God— that He’ll make good on that promise, and then act in light of that promise.
So while the content of God’s promises have been different for various people all throughout Scripture (e.g., Abraham trusted God’s promise that he would be made into a great nation, Sarah trusted God’s promise she would receive a child, etc.), all these people of great faith are described as clinging to a certain promise—and this was faith. As a result, when it comes to the New Covenant, what a Christian is doing when they claim to believe in Jesus is they’re actually hoping and trusting in a particular promise of God—our faith is never ambiguous. The Bible doesn’t know a vague belief. It only knows a powerful belief in something incredibly concrete—and it is always trust in a particular promise that God has given. And the promise, when it comes to the Gospel of Jesus Christ (as presented above) is that a true, genuine believing Christian is trusting the particular promise of God that the death of His Son was, is, and will be sufficient to appease the judicial wrath of God against them as a sinner. Christ was put forth as a ransom. He was the Passover lamb. He was the very sin offering that God Himself provided. It was in Jesus that God executed all of His judicial wrath against sin. And this is the promise we cling to. We trust that Jesus’s resurrection is the divine sign, indeed approval, that the death of Christ was sufficient and acceptable to God as a guilt offering. We trust that the issue of our sin has been resolved by the sacrifice of Christ, and that just as Christ rose from the dead unto eternity, so also all who trust the promise of God will rise in the exact same way.
So yes, we believe on the Lord Jesus Christ for salvation. But we are believing something particular, something unique, something glorious—and it’s nothing short of an amazing, eternal promise. The promises of God are always our hope. And for the Christian, we confess Jesus as Lord and cast ourselves onto His promises.