“Designed to See Light”: Appealing to the Conscience in Apologetics and Evangelism

We are unavoidably moral beings. Perhaps from a Christian view, Western culture today appears to cast off morality or celebrate immorality, and in some cases that might be true. However, conversations with my non-Christian friends, especially as we turn to spiritual or social matters, become deeply moral. It is not that the secular person celebrates immorality; it is quite the opposite. The secular person celebrates a new morality, and in fact, holds to it quite strongly.

This is a marked shift from the 80’s and 90’s when the prevailing reason to disregard the Christian faith was not morality but relativity. To counter a moral claim with “well, that is relative” was the ultimate trump card, even if it was applied inconsistently. Now it is reversed. The secular world now strikes a frequent, powerful tone in its assessments of ideologies it disagrees with. “That is relative” has given way to “that is wrong” or worse: bigoted, abusive, or evil. Assess the language of your secular neighbor—or read the sign in their front yard—and you’ll find moral statements binding the conscience by some secular moral code.

Such a code may vary and shift, but an individual who holds it is bound by it and by it assesses others’ actions and beliefs. Traditionally, this is referred to as the conscience, and today, it reigns supreme. The reality of the human conscience then is a necessary, fascinating, and complex consideration for apologetics and evangelism.

The biblical testimony affirms the reality of conscience. The conscience testifies of God in all human hearts (Romans 2:15). It is a law written on our hearts (Jeremiah 17:1; 31:33) that accuses the wicked and vindicates the righteous (themes also frequently seen in the Psalms). Still, the Bible also acknowledges the reality that consciences are not static. For example, the Corinthian Christians wrestled with the propriety of eating food that had been previously offered to idols. In 1 Corinthians 8:7, Paul considers those with knowledge versus those with weak consciences. He writes, “However, not all possess this knowledge. But some, through former association with idols, eat food as really offered to an idol, and their conscience, being weak, is defiled.” While he acknowledges believers with weak consciences, Paul does want the weak to grow out of weakness and into maturity. As those with weak consciences grow, the knowledgeable should bear with them out of love. Romans 1:21–32 might best capture the spiritual reality of a non-believer’s conscience. The passage concludes that a non-believer not only practices unrighteousness, but also gives approval to others who practice unrighteousness. The dynamic nature of the conscience does not, then, sanction the human heart for its artificial bindings or sinful actions. Still, the point remains in the way Paul presents the nature of human conscience: the human heart is always being shaped, taught, and discipled. The conscience strikes at the very core of the human heart and the very heart of culture—both who we are and what we love and who our world is and what it loves. The evangelistic and apologetic door is open, but the moving target can make the task difficult.

How then might Christians approach evangelistic and apologetic conversations when they take a definitive turn into the moral realm and confront the reality that the Christian conscience disapproves of the very thing the non-Christian’s approves? How might we see a conversation about differing moralities transform into an opportunity for gospel proclamation?

That’s what I want to explore here. First, I will confront two approaches to conscience from Christians and non-Christians, observing how their one-sidedness might fail to account for the rich inner life of the conscience and, thus, neglect the conscience in apologetic and evangelistic appeal. Then, I will turn to the work of Herman Bavinck to offer an integrated approach to the conscience. Lastly, I will draw out the apologetic implications from such an understanding.

Before we explore a conceptual approach to conscience, I want to first evaluate what might be called “street-level” views of the conscience. Most people’s lived reality and relationship to the conscience might be exemplified in two different tendencies: the over-spiritualization of the conscience and over-naturalization of the conscience.

First, let’s consider how the conscience might be over-spiritualized. The Christian might over-spiritualize the conscience in two opposing ways. First, the Christian may regard it as an infallible testimony of God speaking into the lives of all humans in the same way. Applied to life, this may result in a baptized version of “just follow your heart.” When the Christian engages the non-believer, he or she might assume that beneath the surface the non-Christian likely feels a shared remorse. Therefore, an appeal to the conscience may say, “You know deep down this is wrong,” for we are judged on the same law.

The second way Christians may over-spiritualize the conscience is to see it as so obscured by sin that the non-Christian has lost all sense of a testimony from God. The Christian assumes that a non-believer’s conscience has become useless and should not be regarded in conversation.

Assessing these approaches, I believe we can say the former version assumes too much. An appeal to the conscience falls flat when it is found that there is, in fact, not a shared moral framework to make an appeal. Paul speaks of this reality when he describes the conscience of false teachers in 1 Timothy 4:2 as, “seared” (cauterized, lit. Greek). Scar tissue on the conscience renders it numb to the burning conviction of God’s testimony in the human heart. Paul’s imagery is insightful when considering the malformation of conscience. Most habitual sinful behavior does not originate from a predetermined moral conscience opposed to Scripture. In other words, a seared conscience wasn’t numbed in a day. Once hedonistic pleasure becomes habitual, it may seem just that—pleasurable. But testimonies often teach us that it was not always so. The burning of the conscience gives way to cauterizing, then to a scarring effect. The conscience then wraps itself to this reality. The loss of a shared moral framework from which we lose the ability to make an appeal is a progressive work of sin by which, “they are darkened in their understanding” (Ephesians 4:18). In this way, the former approach over-spiritualizes the conscience and forgets the immense effects sin has wrought.

Alternatively, in the latter version we presume too little. When we believe one’s utter depravity has so obscured one’s conscience, we make no appeal to it. A Christian might proclaim the moral backwardness they see in the world today or, how radically immoral they find someone’s life, to which the secular person may ask, “By what standard?” as they walk away, feeling Christians to be exceedingly cruel in their evaluations of other worldviews. In both situations, it feels as if the conscience is better left alone in evangelistic and apologetic conversations. The moral arena is not a helpful place for evangelism to find itself.

On the other end of the spectrum, the secular person regards conscience in a purely natural way—what other option is there? The conscience is an amalgamation of the influences in your life: your upbringing, your intellectual commitments, your life experiences, and more. Indeed, it feels like it is a rite of passage for the modern person to do the work to lay bare their conscience in counseling to untangle these various threads to unburden their conscience from the pieces they did not choose or do not fit with their worldview and, now, commit themselves to a new and improved conscience—one which just so happens to align with the cultural milieu. As a result, the conscience, or the moral realm in general, is not something one’s religious convictions should touch. Certainly, to this person there is no universal conscience beneath the surface.

I do not have the space here to unpack the research around conscience, nor am I qualified to do so. Rather, what I want to offer is an integrated approach to the conscience, accounting for both its robust spiritual depth and the reality of its (mal)formation—from the work of theologian Herman Bavinck—and outline a few apologetic implications of such an approach.

Bavinck’s writing on the conscience spans his career, and his approach to the conscience is theologically, philosophically, and psychologically conversant in the literature of his day, and it offers much clarity to ours.[1] Here, I will focus on his presentation simply titled, “Conscience.”[2]

After giving a brief history of the term in its Greek origins, Bavinck begins his biblical and theological articulation. In the pre-Fall state, Adam’s conscience was silent—at peace, unprovoked. His awareness of self and his awareness of God perfectly coincided.[3] In the state of perfection, mankind fulfilled the law of God. There was no sense in which a voice within might stand over against the person to accuse them. With the pervasive entrance of sin into the world and humanity, the conscience awakens and speaks. Bavinck writes, the conscience “is the knowledge of our fallen moral condition.”[4] Each person continues after the Fall to have the law written on their heart, but the conscience is not the law itself. The conscience is rather the internal testimony from the core of our person that such a law remains written there.

Nevertheless, the rich life of human personality adds layers of complexity to the conscience. Bavinck describes the conscience as the “law of our personality.” At the core of our person, the heart, the law remains written, “but the conscience whereby the subject is bound to that will does change in its witness and judgment, according to the knowledge and development of an individual or of a people.”[5] There is an individuality to conscience that is personally binding for that individual but not others (Bavinck appeals to 1 Cor. 8, 10; Rom. 14). Here Bavinck does not mean to suggest that each person has a moral standard that is equally valid to the conflicting moral standard of another person. Rather, Bavinck is acknowledging, along with Paul, that the subjective nature of conscience will radically vary from person to person. As is the nature of conscience, it places constraints on a person’s moral impulses. One conscience approves of eating food offered to idols and thus morally binds it. The other conscience forbids it and, thus, morally binds it.

While rejecting the Darwinian conception that the conscience is nothing more than survival and social instincts that have developed in humans, Bavinck admits the formative impact of contextual influence on the conscience:

Now it is true and must immediately be granted that in the empirical conscience as we know it from daily experience and observation, there is much that is accidental; it includes many elements that do not automatically belong to the conscience but by means of different circumstances, nurture, status, occupation, etc., have come to be included and have, as it were, grown to be intertwined with conscience. The content of our conscience is derived largely from outside, and thus differs enormously among different peoples. [6]

Quoting Pascal, Bavinck exemplifies the point: “Truth on this side of the Pyrenees, error beyond.”

How does one then relate the reality of a binding law of God on the hearts of all people and the subjective reality of varied consciences? Bavinck himself asks, “Is it entirely blank, merely a ‘tabula rasa’ on which can be written whatever one’s birth, nurture, and environment want to write?” Bavinck answers, “Paul says that the Gentiles, who do not have the law, by nature do the things that are of the law and thus are themselves a law. And it is clear that we cannot make the conscience over into something we want, but often it resists something that we would be willing to adopt. As the ethical organ of human beings it has an affinity for the ethical, like our eye is designed to see the light.”[7]

Though innumerable factors may have been added to one’s conscience for its formation or malformation, the reality persists that God speaks through the conscience. The conscience is the internal wrestling of humans between what we were created to be and who we are in lived reality. The task of humanity, then, is to cultivate that subjective rule to agree with the objective rule made known in God’s revelation.[8]

In summary, Bavinck’s approach to the conscience is neither overly spiritual, disregarding the individuality of conscience as shaped by human communities, nor is it overly natural, abandoning the law of God written on the heart. Bavinck offers an integrated approach that accounts for the subjective experience of consciences in various states of agreement and disagreement with one another, while offering an objective moral ground on which such subjective consciences might even begin to erect their artifices. Applying this approach, let us turn finally to consider its evangelistic and apologetic implications. 

With this theological formulation of an integrated conscience, there are at least four implications one may draw out for apologetic application.[9] First, the conscience is an arena of the knowledge of God that Christians should be motivated to engage. God maintains an internal testimony in humanity, no matter how rebellious. Bavinck writes, “The supreme norm for our life is the divine law that may echo in our conscience as a voice that is dull and unclear and as though from a distance.”[10] He has not left himself without a witness, and when the gospel is proclaimed, that message strikes a chord deep within the human heart. The reverberations might not bubble their way into the cognitive space, but the affective bell might be rung knowing it is there buried. Bavinck writes, “Therein that law of God proves itself to our heart always more as genuinely divine, that it agrees with the depth of our being; therein lies the persistent proof for the truth of Christianity, that it satisfies the deepest needs and pronouncements of our conscience, and Christ fulfills to the fullest within us the law of our own personality.”[11]

Christians should feel emboldened to enter the realm of the conscience. Apologetics is, no doubt, an intellectual endeavor, though never a merely intellectual endeavor. The law being written on the heart of every person likewise means apologetics is also a moral endeavor as well. There is a voice within them that rightly testifies to the knowledge of God that they have suppressed, and the apologist’s work should be to draw that conscience out in as many ways as he or she can. This voice might be (or usually will be) precognitive at first but might rise to conscious thought and volition as the gospel renews the heart and mind.

The anxiety we may feel when a conversation turns toward morality is expected; as we have seen, the moral is immensely personal! However, the affirmation of divinely appointed conscience means there is a common ground created by God in every person.

Second, the conscience has been corrupted by the power of sin and remains captive to it. Romans 1 tells us, “They became futile in their thinking, and their foolish hearts were darkened.” One might say, the foundation of the conscience remains, but the conscience itself has been ruined. Bavinck neatly summarizes this apologetic implication when he writes, “Something can be a sin before God that nonetheless is not against our conscience.”[12]

No matter the nuance, understanding, and clarity of one’s apologetic responses, the eyes of a non-believer’s heart will only be opened by the power of God, freeing them from their bondage and convicting their conscience of sin, a feeling of moral culpability far more existential than the culturally conditioned moral receptors they have added to the conscience (more on that in the next point). Thus, apologetic appeals to the conscience must be always and thoroughly evangelistic.

The ruining of the conscience means part of this work is bringing people to see sin as sin. It may be uncomfortable or risky, but an appeal to the conscience is needed—though it may be the conscience they do not know they have and have suppressed! But it is essential if the goal is for people to see their hostility to God, failure to submit to his law, and the subsequent divine displeasure they incur (Rom. 8:7) such that they would then repent and trust in Jesus for their salvation.

Third, the conscience has artifices added to it that must be accounted for and challenged. While the suppression of the voice of God in the conscience is universal to all humans, the way in which that suppression might manifest itself may look radically different. A person’s upbringing, their education, their technology use, the broader culture, their faith community (or lack thereof), and innumerable other factors impact the boundaries of their conscience. Some of these artifices might have been deeply ingrained in a culture for as long as the culture can recount.

Considering this reality, a Christian should enter into the culture they are seeking to reach with the intention of learning the ways of the people so deeply that they understand the people’s conscience as well as their own. The insight will serve to trace the origins of such artifices but also expose the idolatrous authorities a person serves. When a direct appeal is made to confront a person with their sin and their personal responsibility before God, the pricking of that conscience will be the work of skillful needling rather than a haphazard wounding. One might simply inquire, “Why do you feel that way?” and follow the trail to the core of the person’s life and longings.

Fourth, all consciences accuse, thus the need for forgiveness remains. And artificially construed conscience which excuses sin does not lead to moral freedom, but, in fact, a new bondage. Bavinck adds, “They are bound to the law of their own person, moral being, and that as a personality they can indeed transgress that law but never with impunity, never without remorse and recrimination.”[13] The conscience is the law of our personality that even when man-remade we cannot fulfill perfectly. The malaise of modern life is rife with this reality: we joke on social media about the “Sunday scaries,” we meme our way through the internal disappointment of our repeated failures, we commiserate with others about our inability to sleep as we relive our past mistakes and those we’ve harmed. With no higher power to appeal to for forgiveness, we work to forgive ourselves yet find it far more difficult than we could ever imagine. The reality we face is the accusation of our own conscience without the assurance of salvation.

The Christian has a freeing message for all people who stand condemned by their own hearts: no matter their wrongs, failures, hurts, or history, there is forgiveness offered to them in Jesus Christ. How wonderful is it to tell the burdened conscience, “You may be made white as snow” (Psalm 51:7), “there is no condemnation for those who are in Christ Jesus” (Rom. 8:1), or “God has forgiven you and remembers your sins no more” (Hebrews 8:12). We could go on, for Scripture is so effusive about the forgiveness of God to sinners.

Sin corrupts and enslaves the conscience, and in doing so diminishes our freedom and our flourishing. The opportunity we have as messengers of freedom is the hope of a forgiveness that transcends the human will’s ability to forgive themselves and, instead, offers the hope of a clean conscience washed by the blood of the only righteous one, Jesus Christ.

[1] In Bavinck’s Reformed Ethics, recently compiled from his unpublished manuscripts and class lectures and translated into English, there is a much fuller account of conscience. I will remain focused on his earlier article as a neat summary of his enduring thought on the matter. For a more robust interaction with his thought in this area see Cory Brock, Orthodox yet Modern: Herman Bavinck’s Use of Friedrich Schleiermacher (Bellingham, WA: Lexham Press, 2020); Ximian Xu, “Did Christ Have a Conscience?: Revisiting the Debates on Christ’s (Un) Fallen Humanity,” Theological Studies 82, no. 4 (December 2021): 583–602.

[2] Herman Bavinck, “Conscience,” trans. Nelson D. Kloosterman, The Bavinck Review 6 (2015): 113–26.

[3] Bavinck, “Conscience,” 115.

[4] Ibid., 116.

[5] Ibid., 118.

[6] Ibid., 120.

[7] Ibid., 122.

[8] Ibid., 126.

[9] For more missiological implications of an integrated understanding of the conscience, see: J. H. Bavinck, An Introduction to the Science of Missions (Phillipsburg, N.J.: P&R Publishing, 1993).

[10] Bavinck, “Conscience,” 126.

[11] Ibid.

[12] Ibid.

[13] Ibid., 124.