Unbelievers should tremble at the immense holiness of God. The reality of their sin should frighten and sicken them. And the redemptive work of Christ should thrill them to the core.
Together the truth of those biblical doctrines should provoke a desperate question in the sinner’s heart. It’s the same question that plagued those who heard Peter’s sermon on the Day of Pentecost: “They were pierced to the heart, and said . . . ‘Brethren, what shall we do?’” (Acts 2:37).
The truth of the gospel demands a response from the sinner. Passive indifference isn’t an option. Either unbelievers will reject the facts of the gospel, carrying on with their rebellious lives, or they will desperately cry out for the salvation found only in Christ.
And just as vital as knowing the facts of the gospel, God’s people need to thoroughly understand the response to the gospel that His Word demands. Confusion on this detail—as much as any other point of gospel truth—is a significant hindrance to the church’s evangelistic efforts today.
Scripture makes no mention of walking an aisle, praying a prayer, or signing a card. In fact, God’s Word never points back to an isolated event or an emotional decision for assurance of salvation. There is no biblical basis for that kind of decisional regeneration. Moreover, Jesus isn’t knocking on the door of the sinner’s heart, hoping he will let Him in. He doesn’t need sinful man’s acceptance—we actually need His!
Instead, the gospel call to the sinner throughout Scripture is a simple, succinct command—repent and believe. If we are to faithfully and accurately proclaim the gospel, our message must culminate in a call for the sinner to put his faith in Christ and repent from his sin.
True saving faith is the sinner recognizing his own hopeless condition and trusting Christ as his righteous and sacrificial substitute—the only possible means of escape from God’s just wrath.
The apostle Paul referred to the gospel as “the power of God for salvation to everyone who believes” (Romans 1:16). In his commentary on that passage, John MacArthur writes,
Salvation is not merely professing to be a Christian, nor is it baptism, moral reform, going to church, receiving sacraments, or living a life of self-discipline and sacrifice. Salvation is believing in Jesus Christ as Lord and Savior. Salvation comes through giving up on one’s own goodness, works, knowledge, and wisdom and trusting in the finished, perfect work of Christ.  John MacArthur, The MacArthur New Testament Commentary: Romans 1–8 (Chicago, IL: Moody Publishers, 1991), 55.
There’s nothing sinners can do to gain a right relationship with God—Paul made that very point in Ephesians 2:8-9. “By grace you have been saved through faith; and that not of yourselves, it is the gift of God; not as a result of works, so that no one may boast” (emphasis added). Not only does God provide the means of salvation, He bestows the very ability to lay hold of that salvation through faith in His Son.
That call to believe in the substitutionary sacrifice of Christ rings out in the words of the evangelists in the New Testament. When Jesus spoke to Nicodemus, a high-ranking Jewish scholar, He pointed out “that whoever believes in Him shall not perish, but have eternal life” (John 3:16). When the Philippian jailer cried out to Paul and Silas, “Sirs, what must I do to be saved?” they responded, “Believe in the Lord Jesus, and you will be saved” (Acts 16:30-31). Paul wrote that God is both “just and the justifier of the one who has faith in Jesus” (Romans 3:26). John’s specific purpose for writing his gospel was “that you may believe that Jesus is the Christ, the Son of God; and that believing you may have life in His name” (John 20:31).
God’s Word is clear: Salvation apart from faith in Christ is impossible. As Peter and John declared under trial before the Sanhedrin, “There is no other name under heaven that has been given among men by which we must be saved” (Acts 4:12).
From an evangelistic perspective, it is critically important to distinguish true saving faith from mere mental assent. Faith is not simply an acknowledgment of Christ; it is an active dependence on Him, borne out in the life of the believer in the form of repentance.
Scripture often refers to faith and repentance in tandem, and the two correspond closely in the life of the believer. Turning away from sin in repentance is the natural extension of turning to Christ in faith.
At the same time, there is an important distinction between the two. In his book The Gospel According to Jesus, John MacArthur explains that repentance should never be dismissed as merely another word for belief:
The Greek word for “repentance” is metanoia . . . Literally it means “afterthought” or “change of mind,” but biblically its meaning does not stop there. As metanoia is used in the New Testament, it always speaks of a change of purpose, and specifically a turning from sin. In the sense Jesus used it, repentance calls for a repudiation of the old life and a turning to God for salvation.
Such a change of purpose is what Paul had in mind when he described the repentance of the Thessalonians: “You turned to God from idols to serve a living and true God” (1 Thessalonians 1:9).  John MacArthur, The Gospel According to Jesus, Revised and Expanded Anniversary ed. (Grand Rapids, MI: Zondervan, 2008), 177–78.
Throughout Scripture we see the call to repent from sin and turn to God. Christ warned His followers of the eternal consequences of sinful rebellion, saying “Unless you repent, you will all likewise perish” (Luke 13:5). Paul concluded his sermon on Mars Hill with a command to repent in light of God’s judgment. “Therefore having overlooked the times of ignorance, God is now declaring to men that all people everywhere should repent, because He has fixed a day in which he will judge the world in righteousness” (Acts 17:30–31).
Some argue that calling sinners to repent is adding works to the gospel. But God’s Word is clear that true repentance cannot be mustered up from the unregenerate soul. Instead, like faith, repentance is a gift from God (cf. Acts 11:18; 2 Timothy 2:25).
It is crucial for the biblical evangelist to understand and clearly communicate the vital relationship between faith and repentance, particularly in the current theological landscape.
Throughout church history, there have been those who preached a gospel of easy-believism and cheap grace—one that required no repentance on the part of the converts. That pseudo-gospel is thriving in churches today, giving false assurance of faith to people who have no interest in obedience, holiness, or sanctification. This unbiblical notion of faith apart from repentance would be laughable if it weren’t tragically leading deceived men and women to hell.
In The Gospel According to Jesus, John MacArthur explains the corresponding nature between true faith and repentance.
Clearly, the biblical concept of faith must lead to obedience. “Believe” is treated as if it were synonymous with “obey” in John 3:36: “He who believes in the Son has eternal life; but he who does not obey the Son shall not see life.” Acts 6:7 shows how salvation was understood in the early church: “A great many . . . were becoming obedient to the faith.” Obedience is so closely related to saving faith that Hebrews 5:9 uses it as a synonym: “Having been made perfect, He became to all those who obey Him the source of eternal salvation.”
Obedience is the inevitable manifestation of true faith. Paul recognized this when he wrote to Titus about “those who are defiled and unbelieving. . . . They profess to know God but by their deeds they deny Him” (Titus 1:15–16). To Paul, their perpetual disobedience proved their disbelief. Their actions denied God more loudly than their words proclaimed him. This is characteristic of unbelief, not faith, for true faith always produces righteous works. As the Reformers were fond of saying, we are justified by faith alone, but justifying faith is never alone. The Gospel According to Jesus, 190–91.
The biblical testimony is clear. The gospel call is a call to repent and believe. You can’t have one without the other, and you can’t do either without God empowering those responses.
If we are to faithfully proclaim the message of salvation, we must establish the problem of God’s holiness in contrast to man’s depravity. We must present the solution to that humanly insurmountable problem by preaching the life, death, and resurrection of the Lord Jesus Christ. It is at that point that we are to issue the exhortation to repent and believe, and leave the miraculous work of conversion in God’s sovereign hands.