Since the advent of the so-called Second Great Awakening, which shaped American evangelical theology, piety, and practice so profoundly in the 19th century, many American Christians have simply assumed that revivalist paradigm as correct. Many evangelicals have never seen any other approach to salvation and to the Christian life. An important part of that picture, that approach is the “altar call,” which was given at the conclusion of a “revival” service that consisted of two or three parts. The first part of a revival was dominated by the singing of carefully selected, emotionally powerful songs. The second part of the service was the sermon, which was intended to persuade sinners to come forward at its conclusion to pray the so-called “sinner’s prayer” at the “anxious bench.” Versions of this pattern carried on through the 20th century and the basic structure of the revival service still influence the structure of evangelical and even Presbyterian and Reformed worship services to this day.

Underlying this system for gaining converts is the conviction that once a person has “come forward” and prayed the sinner’s prayer that he must be saved no matter what he may later say and do. It is to this doctrine and practice that some refer when they speak of “once saved, always saved.” This approach to conversion and to the Christian life has been roundly criticized as a form of “easy believism” and “cheap grace.”

The Reformed take a quite different approach to the question of salvation, conversion, and the Christian life:

87. Can they then not be saved who do not turn to God from their unthankful, impenitent life? By no means, for, as the Scripture says, no unchaste person, idolater, adulterer, thief, covetous man, drunkard, slanderer, robber, or the like shall inherit the Kingdom of God (Heidelberg Catechism).

There is a great distinction here that must not be missed. That distinction is between is and because (ground) or through (instrument). What the Reformed Churches here confess is that it is the case that believers will be penitent, i.e., they will recognize sin for what it is. They will recognize their own sin what it is. They recognize and confess the greatness of their sin and misery (Heidelberg Catechism 2–9) and they turn away from it. Believers, those to whom God has graciously, sovereignly granted new life and with it true faith, have repented, do repent and shall repent.

In contrast, however, there are those who profess faith in Christ, who wish to be regarded as believers, whose profession of faith may have been received as genuine in the church. These are called “hypocrites.” They do not actually believe and they are not actually repentant or penitent.

More particularly, those who have been placed under discipline (as discussed under the keys of the kingdom), who have demonstrated their unbelief by refusing to repent, are in grave danger and great jeopardy. That someone has, during a moving (affecting) service, felt a wave of emotion, come forward, felt guilty, or even regret for the consequences of his sins, does not make him a believer. What makes one a believer is true faith, a certain knowledge of Christ and the basics of the Christian faith, assent to their truth, and a personal, heartfelt trust in Christ and in his gospel.

It is not that sinners cannot be saved. Were that so there would be no saved persons. We know from Scripture that there are saved persons. It’s not that the imperfect cannot be saved. Heidelberg 87 is thinking about those who sin impenitently. Christians may indeed commit the gross sins which the catechism quotes from 1 Corinthians 6:9, 10. What distinguishes the believer from the unbeliever is repentance and penitence, which is the fruit of true faith.

This is why it is so important to distinguish between is, because, and through. We are not saved because we are penitent. it is not the ground of salvation. Christ’s righteousness is the ground of salvation. Rather, believers are penitent. If you tell me that you are a believer and you sin impenitently, i.e., you keep on sinning and refused to acknowledge it as sin and turn away from it, then the church should judge you and unbeliever. We are not saved through penitence. Repentance is the fruit of new life and true faith. It is believers who repent. We are not speaking chronologically but logically. Unbelievers cannot repent because they do not have new life and true faith. We are saved by grace alone (sola gratia) through faith alone (sola fide). Only faith apprehends Christ and his righteousness. That is why we confess it to be the only instrument of salvation. We should be particularly on guard against the error that would seek to add obedience to faith (e.g., “faithfulness”) as the instrument of salvation. This error denies the finished work of Christ, who alone has satisfied the righteous law of God, who alone has substituted for us on the cross, and who alone was raised for our justification.

It is the case that believers repent and are penitent, i.e., daily acknowledging the greatness of their sin generally and turning away from particular sins. Thus, when believer comes to another believer to speak to him about a sin, a believer acknowledges his sin. In church discipline cases, at least in confessional Reformed and Presbyterian congregations, it is not the sin itself that is typically the ground of discipline. It is the member’s refusal to acknowledge his sin and to turn from it. When such a person tells the church that the church has no place to speak to him about his sin, then we are dealing with what we call contumacy or a high-handed response to God’s law and to Christ’s Church.

“Easy believism” is a widespread pattern in American evangelical religion. The biblical and Reformed approach to repentance and faith may be a shock to the system. That someone has walked the aisle or prayed the prayer means little if it is not accompanied by evidence of true faith. Chief among those evidences is not perfection but penitence. It is to this sort of faith that James referred when he complained that some Christians professed faith but there was no evidence of their faith (James 2:14-15). Such a faith, that is a mere profession of faith that is, in fact, not true faith at all, cannot indeed save anyone since it is not faith. It is not, as Rome says, that our good works makes faith what it is (fides formata caritate) or that we must augment our faith with good works (moralism) but that it is the case that living trees produce fruit.

Here are all the posts on the Heidelberg Catechism.