This article gathers my reflections on a particular approach to apologetics, shaped largely by what I have learned from reading Catholic theologians and Catholic writings. My hope is that this method can serve all Christians —deepening our common witness, for the glory of God and the love of others.
Setting the Scene
Imagine someone you trust deeply—someone whose word reliably moves you to listen (call this person X). Now imagine a complete stranger approaches you and hands you a sealed letter, saying, “This is a message from X.” How would you respond? You have no reason to trust the messenger, and you cannot immediately verify the stranger’s connection to X. In that situation, it would be unreasonable to treat the letter as authentic simply by reading it and deciding whether it sounds like X. Even if the content seems consistent with what X might say, that alone does not prove the letter is genuinely from X; a convincing imitation or a coincidence remains possible. Additionally, the content could seem unlikely to be from X, but still that doesn’t imply that the message isn’t from X. So you are stuck: you cannot confidently affirm the letter’s origin, and without knowing its origin, you cannot responsibly trust its contents.
Now add one crucial detail. Suppose you know X uses a distinctive signature and a seal—something you can recognize and that cannot be forged. You examine the envelope and see that seal clearly impressed, with the signature in the expected form. At that point, even though the letter arrived through a stranger, you have solid grounds for confidence that it truly comes from X. And because you already trust X, you can then read the message with trust—not because the content persuaded you that it must be from X, but because you have independent reason to believe who the message is from.
This is the basic pattern that should guide our approach to divine revelation: confidence in the message rests first on credible confirmation of its source, and only then on receiving its contents in trust.
Definitions
Before outlining the method, it will help to define a few key terms. During the high period of Scholasticism (roughly the 13th and 14th centuries), St. Thomas Aquinas, drawing on Aristotle, carefully distinguished different ways we can hold beliefs and the kinds of reasons that ground them. He describes three primary modes of assent:
- Knowledge (Scientia):
- What it is: Assent to a proposition because you see (directly or by demonstration)
- Ground of assent: Evidence intrinsic to the thing
- Immediate evidence (i.e. the object is red or some necessary truth such as 2+2 = 4)
- Demonstration from known principles (i.e. if all humans are mortal and Socrates is human, then Socrates is mortal)
- Certainty: Very high certainty, because the mind is “forced” by the object as understood. If you genuinely have knowledge in this sense, you hold the opposite as impossible.
- Key Mark: The intellect sees why it must be so
- Opinion (Opinio):
- What it is: Assent to a proposition with fear that the opposite might be true
- Ground of assent: Reasons that incline but don’t compel
- Incomplete evidence
- Probabilistic considerations
- Inductive generalizations with acknowledged gaps
- Certainty: Low to moderate depending on the strength of reasons, but structurally it remains fallible and revisable. You don’t claim necessity, you claim likelihood
- i.e. This interpretation of that historical event seems most likely
- Key Mark: Your mind leans one way, but you remain aware you might be wrong.
- Faith (fides): Here we will specifically focus on divine faith
- What it is: Assent to a proposition based on the authority of the revealer, not because you see the truth intrinsically or can demonstrate it.
- Ground of assent: Testimony/authority — ultimately God revealing (who cannot deceive or be deceived)
- Certainty: Highest certainty — not because the content is self-evident to you, but because the source is infallible if truly God
- So faith is more certain than opinion, in a real sense, firm — but it is not “knowledge” because you do not see the truth by intrinsic evidence (i.e. the Trinity, the resurrection, etc)
- Key Mark: You do not see it; you hold it because a trustworthy authority reveals it.
Two clarifications are worth making. First, as I am using the term here, faith can refer both to human faith and to divine faith. Human faith is assent to a claim on the testimony of another person; divine faith (as explained above) is assent to what God reveals on God’s own authority. A simple example of human faith is the belief that your parents are truly your parents. In most cases, people do not obtain a blood test to verify this. Instead, they accept it on the testimony of those who raise them, supported by the countless signs across a lifetime that these people really are their parents. But this also shows why testimony matters so much: when someone discovers later in life that they were deceived about their parentage, the result can be profoundly painful and destabilizing. Second, the fact that a claim can be held under a particular mode of belief does not mean that everyone who accepts that claim accepts it under the same mode. To continue the previous example: someone could come to know that two people are their biological parents through a scientific test, such as a blood test. In that case, the person assents to the claim on the basis of knowledge. Another person, however, may assent to the very same claim primarily on the basis of testimony—that is, by faith in the human sense. This highlights an important point: two people can affirm the same proposition and even share much of the same background information, yet do so through different modes of assent. As a result, they may also experience different degrees and kinds of certainty about what they believe.
Step 1: God Exists
At this point, the approach I intend to explain may be clearer. A central claim of Christianity is that our Lord Jesus Christ is a divine legate—a messenger sent by God to deliver a message to God’s creatures. This theme runs throughout the Gospels, and it appears explicitly in the Gospel of John when Jesus says,
“I have come down from heaven, not to do my own will, but the will of him who sent me” (John 6:38).
This is, of course, an extraordinary claim, and it should not be accepted uncritically. A brief look at history—and even at the present—shows that many individuals have claimed to speak on God’s behalf. So before we move too quickly, we need to step back and examine the Christian claim more carefully. Unfortunately, many people today do not believe that God exists at all. This raises an obvious difficulty: how can we meaningfully argue that Jesus was sent by God if a person does not yet believe that God exists? The existence of God is not presented by the Catholic tradition as a matter of blind assertion: it is held to be knowable by natural reason. In other words, by reflecting on what we can know about reality, a person can arrive at the conclusion that God’s existence is necessary. For that reason, anyone who hopes to share the Gospel effectively must often begin here—helping others see that belief in God is not merely a cultural inheritance or a private feeling, but a conclusion that can be supported by rational inquiry. Five Proofs of the Existence of God, by Edward Feser, makes this point forcefully in its introduction (and it is well worth reading). He states,
“A long line of thinkers from the beginning of Western thought down to the present day — Aristotelians, Neo-Platonists, Thomists and other Scholastics, early modern rationalists, and philosophers of some other schools too, whether pagans, Jews, Christian, Muslims, or philosophical theists — have affirmed that God’s existence can be rationally demonstrated by purely philosophical arguments. The aim of this book is to show that they were right, that what long was the mainstream position in Western thought ought to be the mainstream position again. The real debate is not between atheism and theism. The real debate is between theists of different stripes — Jews, Christians, Muslims, Hindus, purely philosophical theists, and so forth —and begins where natural theology leaves off.”1
What this implies is that it helps to have a solid grasp of at least one strong argument for God’s existence—ideally, one that also points naturally toward the core divine attributes associated with classical theism (for example, God’s necessity, unity, and transcendence). Many of these arguments are admittedly abstract. For that reason, anyone who hopes to share them effectively should be able to translate the underlying reasoning into clear, concrete language—using examples and illustrations that make the key steps easier to follow. The goal is not to overwhelm someone with technicalities, but to help them see how the conclusion is meant to follow: that God exists, not as a convenient hypothesis, but as something required by the realities we encounter.
Step 2: God can communicate with His creatures
Once it is firmly established that God’s existence is not merely probable (that is, accepted as an opinion based on likely arguments) but necessary—a conclusion reached by reasoned demonstration—the discussion can move to Christianity’s central claim: that Jesus was sent by God to deliver a message to humanity. The next step is to show that it is at least possible for God to communicate with His creatures. In my view, this point follows fairly naturally from what classical theism has already concluded about God. If God is omnipotent and sustains all things in existence at every moment, then it is difficult to see why communication with creatures would be beyond His power. Whatever additional questions might arise about how God would communicate, the basic claim that God can communicate seems to follow directly from who God is understood to be. This is more clearly articulated in the work Laying the Foundation: A Handbook of Catholic Apologetics and Fundamental Theology. The author, Joseph Clifford Fenton, says
“Essentially this revelation is a speaking by God to man in order to teach him. Such a thing is obviously possible since that God whose existence can be clearly demonstrated according to the natural process of human reason is an intelligent Being, who can express His knowledge, direct that expression to those creatures which are dependent upon Himself, and can actually see to it that the intelligent creature understands both the truth which God has expressed to him and the fact that this statement has been made by God. Moreover, it is possible also from the viewpoint of man, to whom the communication is made, since man is capable of learning and of knowing about God and in no way loses perfection through receiving this instruction from his Creator.”2
We also want to establish that God is capable of revealing truths to human beings that we could not discover on our own. This, too, follows naturally from what classical theism affirms about God’s attributes. If God is the source of all truth and possesses perfect knowledge, then it is entirely coherent that He could disclose realities that exceed the limits of unaided human reason. Clifford expresses the point as follows:
“… we can show that God could actually communicate to man information which man himself does not possess, since the most obvious characteristic of human understanding is its limited and progressive quality. The First Cause is not merely intelligent; He is Intelligence, a subsisting Act which apprehends the full measure of knowable reality. This we know by the natural process of human reason.”
Step 3: The Motives of Credibility
Now that the first two claims have been addressed, the final—and most decisive—question is whether Jesus truly was sent by God. This point matters enormously because of what it would mean for all humanity if God has in fact chosen to deliver a message to His creatures. As in the opening illustration, it would be unreasonable to believe someone simply because they claim to be sent by God. And it is equally misguided to assess whether a message comes from God solely by analyzing its contents. Yet this is where many discussions often go off track. Many unbelievers respond to Christian claims by immediately attacking particular teachings of Jesus—sometimes with sharp objections or moral criticism. The reaction is understandable: Jesus’ teachings can be demanding, and he himself acknowledges their difficulty. Still, there is an important mistake here, because it skips a necessary step. Before debating whether the teachings are acceptable, one must first ask a prior question: Has Jesus truly been sent by God? If the answer is yes, then the appropriate response is not to place ourselves as judges over the message, but to listen with the seriousness owed to God’s authority. If God speaks, we have every reason to attend: He is all-knowing, and we are wholly dependent on Him for our very existence.
We should recognize that accepting a claim on the authority of God’s revelation is a serious matter and should never be treated lightly. Far from honoring God, a person would actually offend Him if he were to accept—without adequate reason—that some statement had truly been communicated by the Creator. For that reason, a sound judgment about a revelation’s credibility is of the highest importance. Clifford states it as such,
“In general a judgment of credibility involves three elements. First of all, the man who receives a message on the authority of the one who has communicated it to him, rather than by reason of any evidence of truth manifest in the communication itself should know whether the statement is genuine, that is, whether it has actually come from the person who was supposed to have sent it. Then, he should know whether the person who has sent the message actually has knowledge of the object about which he wishes to instruct. Finally, the “destinary” should be able to judge whether the sender of the message actually intends to tell the truth.”
Given the divine attributes established through natural arguments for God’s existence, it is clear that, in God’s case, the only relevant consideration is the first point. Because God is all-knowing and perfectly truthful, He fully understands whatever He intends to teach and cannot deceive.
So how can one ascertain that God has sent a messenger with a message that is credible? Clifford says
“The standard by which we determine the divine origin of a particular or any communication is analogous to that which we utilize in ascertaining the origin of any other message which we might receive. We recognize a message from another human being principally by means of his signature. This signature is so intensely personal that it can be considered as perfectly proper only to the individual human being involved. Others may counterfeit his signature, but they can never duplicate it. A message which bears the signature or the seal of a man is rightly considered as emanating from his person and as worthy of credence as he himself is. Although God Himself is invisible to bodily eyes, there are certain visible effects which He alone can produce, and which are manifestly distinct from and superior to any and all counterfeits of these same effects. Such works, evident in themselves and manifestly attached to the body of a doctrine which claims to be revealed, show this doctrine to be of authentic divine teaching. The all-wise and all-just God could never permit Himself to deceive His creatures by attaching His signature to a doctrine which He knew to be false. He could never allow Himself to be called in as a witness and to attest a claim that was unsubstantiated.”
Therefore, our task as Christians is to present evidence accessible to ordinary human inquiry that Jesus Christ truly lived, that He actually taught the doctrine attributed to Him, that He claimed this teaching was a divine message to be received as such, and that He offered compelling signs in support of that claim—signs intended to show that His teaching was, in fact, revealed by God. This is where the historical evidence is extremely valuable as well as a reference to the four gospels as purely historical documents (even though as Christians we know they are divinely inspired documents authored by God).
Summary
Each of these steps is meant to lead a person to the conclusion that our Lord truly was a divine legate. From there, one can make the assent of divine faith, which (as defined here) is the intellect’s assent based on the trustworthiness of God’s testimony. This assent is not a merely intellectual reflex; it is commanded by the will which is moved by the grace of the Holy Spirit. Once we have made a judgment of credibility—once we have, so to speak, recognized God’s “signature” in the works of Christ—we can hold the content of Christ’s message with firm certainty. This remains true even when that message includes truths that could also be known by natural reason. For if God has revealed something, we can accept it on God’s authority alone, since God can neither deceive nor be deceived. One reason I find this approach so helpful is that it is often clearer, and in practice less burdensome, for someone who is sincerely seeking. When I began to look more seriously into Christianity, I found myself drawn to the conclusion that Christianity was true because it seemed like the most plausible worldview given the alternatives. That way of reasoning is common in popular apologetics, especially online. And in a sense it makes perfect sense: if Christianity is true, it will typically appear to have the strongest overall support. The concern raised by many theologians, however, is about what they call the formal object of faith—that is, the decisive reason why we believe. If our belief rests primarily on what is most likely, then our assent is grounded in something closer to opinion than to faith in the strict sense. And opinion, as we noted earlier, is one of the weakest modes of assent: it can shift as new arguments or evidence arise. Of course we should always be open to honest inquiry and new information, but notice the key point: when Christian faith is properly understood, the ultimate ground of assent is not a changing balance of probabilities. It is God’s act of revealing—an anchor that does not change even as our understanding grows or as particular evidences are clarified.
Another reason I prefer this method is that claiming “Christianity is the most likely worldview” often implies that a person has carefully examined many competing worldviews and weighed the arguments for each. In practice, that can be cumbersome and exhausting. It requires sustained attention, familiarity with multiple traditions, and the patience to sort through many overlapping claims and counterclaims. Most people—especially those who do not see religion as especially important—are unlikely to undertake that kind of comparative project in a serious way.
For that reason, I think it matters to present an approach that is more direct: one that leads to the conclusion most efficiently, namely, that Christianity is true and ought to be accepted because God has spoken to humanity.
To summarize, the process begins by showing that God’s existence can be known through natural reason. Once that point is established, the rest follows more easily. Any worldview that denies God’s existence outright, or that proposes a “divine” being incompatible with the attributes of classical theism, can be set aside. From there, the question becomes which remaining religions credibly present a genuine divine messenger, and this is where the judgment of credibility must be applied. On my understanding, this narrows the field to four major contenders: Judaism, Christianity, Islam, and Mormonism. One reasonable strategy is to consider them in historical order, since continuity is itself commonly proposed as a motive of credibility: if God reveals, He cannot contradict Himself. Later claims must therefore be consistent with what God has previously made known. That said, Judaism presents a special challenge for modern inquirers. Whatever one concludes about its divine origin, it was historically bound to a particular people and covenant, and its prophetic office is not as straightforward to evaluate today through the claims of a single, universally public divine legate. For that reason, a practical entry point for many seekers is to begin with Christianity and then evaluate subsequent claimants in light of it. My conviction is that anyone who follows this process with sincerity will come to see that Jesus truly was a divine legate, whereas the later claimants were not.
I want to conclude by briefly explaining why I have used the traditional Catholic definition of faith in this post. In the course of my reading, it has become increasingly clear to me that Christian faith is meant to be firm and certain—not because we can reason through every nuance of revelation, and not because we fully understand everything Jesus teaches. Rather, faith is firm because of its foundation: God has spoken. Fr. Mathias Scheeben gives a beautiful summary of faith’s irrevocably firm assent:
“Regarded subjectively, faith can and must first be essentially an altogether decisive assent, which not only practically suppresses any doubt about the truth and any fear about the untruth of what is believed, but includes the most complete conviction that what is believed cannot be untrue; for only such an assent corresponds to the dignity and strength of the motive—the unerring truth of God— through which the mind allows itself to be determined in faith, and to which it can surrender in no other way than with unconditional trust. Consequently faith is essentially different not only from mere opinion, which entirely lacks the decisiveness of certainty, but also from simple so-called practical or moral conviction, whereby one is content merely because on the one hand at the moment one has no positive reasons for doubt and on the other hand one cannot attain complete certainty. It requires and possesses unconditional decisiveness and unconditional fearlessness, in other words, absolutely perfect certainty. This is de fide.”3
Once we can reasonably ascertain that God has spoken, we can offer what Latin theologians called the sacrificium intellectus—the “sacrifice of the intellect”—that is, the humble submission of our understanding in reverent homage to the word of God. This is the process I believe everyone should follow in order to evaluate the truth of the Christian claims. I understand that many people’s first instinct is to judge the contents of the message before they have established whether they can accept it at all. But if we know that God has revealed something, then we can follow King David in saying,
“Your testimonies are very sure; Holiness adorns Your house, O LORD, forever.” (Psalm 93:5)
Our Lord came to deliver divine revelation intended to bring about obedience. For that reason, we are not meant to approach the body of doctrine as though we must first decide whether it is acceptable before we determine whether we ought to assent to it. St. Paul the Apostle makes this especially clear at the close of his Epistle to the Romans:
“Now to Him who is able to establish you according to my gospel and the preaching of Jesus Christ, according to the revelation of the mystery kept secret since the world began but now made manifest, and by the prophetic Scriptures made known to all nations, according to the commandment of the everlasting God, for obedience to the faith — to God, alone wise, be glory through Jesus Christ forever. Amen.” (Romans 16:25-27)
The Sovereign King of all creation has spoken; therefore, as Christians, we listen.
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