Chapter 1

Defending the Faith: Approaching World Religions

by Dr. Kenneth Gentry, Jr.

Biblical Christianity is a philosophy of life (worldview) surrounded by many opposing philosophies (worldviews). In this book we are promoting biblical Christianity over competing worldviews.

God calls upon Christians to “sanctify the Lord God in your hearts, and always be ready to give a defense [Gk., apologia] to everyone who asks you a reason for the hope that is in you, with meekness and fear” (1 Peter 3:15; NKJV). As we obey Him, we must defend the faith in such a way that it “sanctifies the Lord” in our hearts. This requires that we defend the faith from a position of faith. Simply put, the way that we argue for the faith must be compatible with the faith for which we argue.

In defending the faith we are engaging in what is called “apologetics.” The English word “apologetics” is a compound of two Greek words apo (“from”) and logos (“word”). Basically, an apologetic is a word from someone in his or her defense. It was originally a judicial term used in a court setting whereby someone defended himself from accusations.

The verb form of the word (apologeomai) occurs ten times in the New Testament (Luke 12:11, 21:14; Acts 19:33, 24:10, 25:8, 26:1, 26:2, 26:24; Romans 2:15; 2 Corinthians 12:19). The noun (apologia) appears eight times (Acts 22:1, 25:16; 1 Corinthians 9:3; 2 Corinthians 7:11; Philemon 1:7, 1:16; 2 Timothy 4:16; 1 Peter 3:15). Several of these appearances involve an actual court defense (e.g., Luke 12:11, 21:14; Acts 19:33, 24:10, 25:8, 25:16; etc.).

Gradually, apologetics evolved over time to become a branch of Christian theology that engages in a reasoned defense of the Christian faith. It sets forth the rational basis upon which the faith rests, and through that it challenges all forms of non-biblical truth claims. It challenges unbelieving thought with the confidence of “come, let us reason together” (Isaiah 1:18).

Unfortunately, too many defenses of the Christian faith today cede the method of approach to the unbeliever by arguing on his terms. This generally ends up “proving” at best only the possibility that a god exists—not the certainty that the God of Scripture exists. But we should argue from a “presuppositional” perspective that builds on the sure foundation of that which we believe. That is, we must believe that God’s Word is the absolute authority in all areas of life and thought. This method of apologetics is called “presuppositionalism.”

But what is presuppositionalism? And how does it effectively challenge all forms of unbelieving (non-biblical) thought? Answering these questions is the task of this chapter. To understand the presuppositional apologetic method, we must begin by considering the role of presuppositions in thought.

The Role of Presuppositions in Thought

As we begin to engage presuppositionalism, we must understand the following.

The Uniformity of Nature and Thought

We exist in what is known as a “universe.” The word “universe” is composed of two Latin parts: “uni” (from unus, meaning “one,” as in “unit”) and “verse” (from vertere, meaning “turn”). It speaks of all created things as collective whole. This word indicates that we live in a single unified and orderly system that is composed of many diverse parts. These parts function coordinately together as a whole, singular, rational system.

We do not live in a “multiverse.” A multiverse state of affairs would be a disunified, totally fragmented, and random assortment of disconnected and unconnectable facts. These unconnectable facts would be meaninglessly scattered about in chaotic disarray and ultimate disorder.

The concept of a “universe” is vitally important to science, for the very possibility of scientific investigation is totally dependent upon the fact of a “universe”—an orderly, rational coherent, unified system. If reality were haphazard and disorderly, there would be no basic scientific and mathematical laws that govern and control all the various physical phenomena of reality. And if this were so, there could be no unity at all in either reality itself, in experience, or in thought.

In such a multiverse, each and every single fact would necessarily stand alone, utterly disconnected from other facts, not forming a system as a whole. Consequently, nothing could be organized and related in the mind because no fact would be related to any other fact. Thus, science, logic, and experience are absolutely dependent upon uniformity as a principle of the natural world.

Uniformity and Faith

But now the question arises: how do we know assuredly that the universe is in fact uniform? Has man investigated every single aspect of the universe from each one of its smallest atomic particles to the farthest corners of its galaxies—and all that exists in between—so that he can speak authoritatively? Does man have totally exhaustive knowledge about every particle of matter, every movement in space, and every moment of time? How does man know uniformity governs the world and the universe?

Furthermore, how can we know that uniformity will continue tomorrow so that we can conjecture about future events? And since man claims to have an experience of external things, how do we know our experience is accurate and actually conforms to reality as it is? That is, how do we know that our senses are basically accurate and our memory is essentially reliable?

Such questions are not commonly asked, even though they are vitally important. The point of these questions is to demonstrate an important truth: we must realize that any and every attempt to prove uniformity in nature necessarily requires circular reasoning. To prove uniformity one must assume or presuppose uniformity.

If I set out to argue the uniformity of the universe because I can predict cause and effect, am I not presupposing the uniformity and validity of my experience? How can I be sure that my experience of cause and effect is an accurate reflection of what really happens? Furthermore, am I not presupposing the trustworthy, uniform coherence of my own rationality—a rationality that requires uniformity?

The issue boils down to this: since man cannot know everything he must assume or presuppose uniformity and then think and act on this very basic assumption. Consequently, the principle of uniformity is not a scientific law but an act of faith that undergirds scientific law. Thus, adherence to the principle of uniformity—though basic to science—is an intrinsically religious commitment.

Presuppositions in Thought

Scientists follow a basic pattern in discovering true scientific laws. First, they observe a particular phenomenon. Then on the basis of their observations they construct a working hypothesis. Next, they perform experiments implementing this hypothesis. This is followed in turn by attempting to verify the experiments performed. Then a verified hypothesis is accepted as a theory. Finally, a well-established theory is recognized as a scientific law that governs in a given set of circumstances.

Thus, the basic pattern of scientific activity is:

  1. observation
  2. hypothesis
  3. experimentation
  4. verification
  5. theory
  6. law

Christians agree wholeheartedly with the validity of this scientific methodology. We accept the notion of a uniform universe that allows for such, for “in the beginning God created the heavens and the earth” (Genesis. 1:1; NASB).

Physicist Thomas Kuhn, in his epochal 1962 work titled The Structure of Scientific Revolutions, notes that scientists must work from certain preconceived ideas, certain presupposed concepts about things in order to begin formulating their theories and performing their experiments.1

That presuppositions are always silently at work is evident in that when dealing with a particular problem, scientists select only a few basic facts to consider while rejecting or overlooking numerous others. They perform certain types of experiments while neglecting others. And they do this in keeping with their presuppositions. One of the most basic presuppositions held by scientists is the one we are considering: the universe is in fact one orderly, logical, coherent, predictable system. Were this not assumed, then science could not even get off the ground.

But, as a matter of fact, there are numerous presuppositions that all rational people hold that play a vital role in all human thought and behavior. The various presuppositions we hold govern the way we think and act, all the way down to how we select and employ specific facts from the countless number presented to us each moment. Basic presuppositions are the foundation blocks upon which we build our understanding of the world about us. Presuppositions are the very basis for what is known as our “world-and-life” view (or “worldview”).

A worldview is the very framework through which we understand the world and our relation to it. Everyone has a particular way of looking at the world that serves to organize ideas about the world in his mind. This worldview must be founded on basic presupposed ideas that we hold to be truth. We begin with certain presuppositions and build from there in our learning, communicating, behaving, planning, and so forth. Because of this, we must recognize the impossibility of neutrality.

The Impossibility of Neutrality

Everyone holds to presuppositions. No one operates—or even can operate—in a vacuum. We simply do not think or behave “out of the blue.” It is impossible to think and live as if we were aliens having just arrived to this world from a radically different universe, totally devoid of all knowledge of this world, absolutely objective and utterly impartial to ideas about truth. People behave in terms of a basic worldview that implements their conceptions regarding truth.

Consequently, neutrality in thought is impossible. Each person—the philosopher and scientist alike—has his own bias. This bias has predetermined the facts on the basis of his presuppositions. Yet almost invariably, scientists claim to be presenting neutral, unbiased, impartial, and objective facts in their research. But man is not and cannot be truly objective and impartial. All thinking must begin somewhere!

All thinking must have some fundamental, logically-primitive starting point or presupposition. At the very least, we must presuppose the reality of the external world, the rationality of mental activity, the compatibility between external reality and the mind, and the uniformity of nature, that is, the law of cause and effect. As noted previously, a certain faith is necessary in the selection and organization of the several facts chosen from the innumerable set of facts flowing toward us in every moment of experience.

Clearly, presuppositions are necessarily self-authenticating or self-evidencing. Facts are inseparable from their interpretation. Facts cannot stand alone. They must be understood in terms of some broad, unified whole or system. They must be organized in our rational minds in terms of their general relationships to other facts and principles.

This leads us then to our most basic questions: Which system of thought can give meaning to the facts of the universe? Which worldview can provide an adequate foundation for reality? Why is the world in which we live conducive to rational thought and behavior? What is the basis for an orderly universe?

Worldviews in Collision

When we contrast Christian thought with non-Christian thought we must realize that we are not contrasting two series of isolated facts. We are not comparing two systems of truth that share a basically similar outlook and that have only occasional differences between them at specific turns. We are contrasting two whole, complete, and antithetical systems of thought.

Each particular item of evidence presented in support of the one system will be evaluated by the other system in terms of the latter’s own entire implicit system with all of its basic assumptions. Each fact or piece of data presented either to the Christian or the non-Christian will be weighed, categorized, organized, and judged as to its possibility and significance in terms of the all-pervasive worldview held.

Consequently, it is essential that we see the debate between the Christian and the non-Christian as between two complete worldviews—between two ultimate commitments and presuppositions that are contrary to one another. Two complete philosophies of reality are in collision. Appealing to various scientific evidences will be arbitrated in terms of the two mutually exclusive and diametrically opposed, presupposed truths held by the systems.

Thus, the debate between the Christian and the non-Christian must eventually work its way down to the question of one’s ultimate authority. Every series of argument must end somewhere; one’s conclusions could never be demonstrated if they were dependent upon an infinite series of arguments and justifications. So all debates must terminate at some point—at some premise held as unquestionable. This is one’s foundational starting point, one’s ultimate authority or presupposition.

The question that surfaces at this point is this: which system of truth provides the foundational preconditions essential for observation, reason, experience, and meaningful discourse? Thus, which faith system should be chosen: the Christian or the non-Christian?

The Christian System and Presuppositions

What is the Christian’s starting point? What is his most basic presupposition upon which he builds his entire worldview? Where do we begin our argument?

Christian thought holds as its most basic, fundamental, all-pervasive, and necessary starting point or presupposition, the being of God who has revealed Himself in Scripture. Thus, our presupposition is God and His Word. The Scripture, being His own infallible Word (2 Timothy 3:16), reveals to us the nature of the God in whom we trust.

God is self-sufficient, needing absolutely nothing outside of Himself (Exodus 3:14; John 5:26). All else in the universe is utterly dependent upon Him (Colossians 1:17; Hebrews 1:3). God is the all-powerful Creator of the entire universe (Genesis 1:1; Exodus 20:11; Nehemiah 9:6). God is personal, thus giving meaning to the vast universe (Acts 17:28). And God has clearly and authoritatively revealed Himself in Scripture (2 Peter 1:20–21), so we may build upon His Word as truth (Psalm 119:160; John 17:17).

The entire Christian system of thought is founded solidly upon this God—the all-ordering God of Scripture (Psalm 33:9; Isaiah 46:10). We presuppose God for what He is. If God exists and demands our belief in Scripture, we cannot challenge or test Him in any area (Deuteronomy 6:16; Matthew 4:7). We recognize the independence of God and the utter dependence of man and the universe.

Because of this, we do not have to exhaustively know everything in order to be sure of anything. God knows all things and has revealed to us in His Word the truth of uniformity (Genesis 8:22; Colossians 1:17; Hebrews 1:3) and all other truths we need in order to reason and to function in His world.

The Non-Christian System and Presuppositions

Against this presupposed system, what does the non-Christian presuppose as ultimate truth? What does the secularist have to offer as its ultimate authority?

The non-Christian must ultimately explain the universe not on the basis of the all-organizing, self-sufficient, all-wise, personal God as his starting point. In rejecting God and His Word, the default position for all other worldviews must be established on the ideas of man to one degree or another. Perhaps one of the most popular worldviews of man today is secularism, also known as humanism. It holds that reality is ultimately rooted in the nebulous, chaotic, and impersonal world. Due to its widespread and influential presence in our culture, this popular religious view will be compared and contrasted to the Christian worldview in the remainder of this chapter.

The secularist asserts that the universe was produced by a combination of impersonal chance plus an enormous span of time. Thus, in this worldview the ultimate starting point and the all-conditioning environment of the universe is time plus chance.

Because the unbeliever’s worldview is based upon time plus chance, rational science is rooted in the irrationality of chance. The scientist cannot speak of design or purpose in the universe because there is no Designer or purpose. There can be no goal or purpose in a random system.

On this view, secular science must by the very nature of its non-Christian commitment assume facts to be bits of irrationalism strewn about awaiting rationalization by man. Thus, modern secular science is schizophrenic. On the one hand, everything has its source in random, ungoverned chance. On the other hand, evolution assumes all is not random, but uniform. It holds that all is ungoverned, yet, nevertheless, is moving in an upward direction from disorder to order, from simplicity to complexity.

In this regard, Christian apologist Dr. Cornelius Van Til has noted: “On his own assumption his own rationality is a product of chance. . . . The rationality and purpose that he may be searching for are still bound by products of chance.”2 To prove a rational universe by chance, man must believe the rational is the product of, and is dependent upon, the irrational.

Not only is all of reality founded on chance, but this leaves man to be the final criterion of truth. Man—sinful, fallible, finite man—becomes ultimate in the non-Christian system.

Presuppositions Make a Difference

Now let us consider four important areas of philosophy that govern our outlook.


When asked to give the basis and starting point for the orderly universe and all external reality, the Christian points to the self-contained, ever-present, all-powerful, all-wise, infinitely rational God of Scripture.

When the non-Christian secularist is asked to give the basis and starting point for the orderly universe and external reality, he points literally to . . . nothing. All has risen from nothing by the irrational mechanism of chance.

When asked if something can miraculously pop into being from nothing in an instant, the non-Christian vigorously responds in the negative. Instant miracles are out of the question. But when asked if something can come out of nothing if given several billion years, the non-Christian confidently responds in the affirmative. As Dr. Van Til has noted, the non-Christian overlooks the fact that if one zero equals zero, then a billion zeros can equal only zero.

Thus, the Christian has a more than adequate reason for the universe, whereas the non-Christian has no reason whatsoever.


The Christian establishes his theory of knowledge on the all-ordering, all-knowing God of Scripture. God has instantaneous, true, and exhaustive knowledge of everything, and He has revealed to man in the Bible comprehensive principles that are clear and give a sure foundation for knowledge. Such a foundation ensures that what man does know (although he cannot know all things), he can know truly. Knowledge does work because man’s mind as created by God is receptive to external reality and is given validity by God Himself. We are, after all, made in the image of the logical, all-knowing God of truth (Genesis 1:26–27, 9:6)!

On the other hand, the non-Christian must establish his theory of knowledge on the same foundation upon which he establishes reality: nebulous chaos and irrational chance. If followed consistently, the non-Christian theory of knowledge would utterly destroy all knowledge, causing it to drown in the turbulent ocean of irrationalism. There is no reason for reason in the non-Christian system. The concepts of probability, possibility, order, rationality, and so forth, are impossible in a chance and purposeless system.

Thus, the Christian has a sure foundation for knowledge, whereas the non-Christian has none.


When we consider the issue of moral law, the standard for judging right and wrong, again the question must be settled in terms of one’s foundational system.

For the Christian, morality is founded upon the all-good, all-knowing, everywhere present, all-powerful, personal, and eternal God of Scripture. His will, which is rooted in His being and nature, is man’s standard of right. Since God is all good (Psalm 119:137; Mark 10:18) and all-knowing (Psalm 139; Proverbs 15:3), moral principles revealed in Scripture are always relevant to our situation. Since God is eternal (Psalm 90:2, 102:12), His moral commands are always binding upon men.

For the non-Christian there is no sure base for ethics. Since reality is founded on nothing and knowledge is rooted in irrationalism, morality can be nothing other than pure, impersonal irrelevance. In such a system as presupposed by non-Christian thought, there are no—indeed, there can be no—ultimate, abiding moral principles. Everything is caught up in the impersonal flux of a random universe. Random change is ultimate in such a system. And because of this, ethics is reduced to pure relativism. Non-Christian thought can offer no justification for any moral behavior whatsoever.


To the question of whether or not there is any significance and meaning to the universe and to life, the Christian confidently responds in the affirmative. There is meaning in the world because it was purposely and purposefully created by and for the personal, loving, all-ordering, eternal God of Scripture (Nehemiah 9:6; Psalm 33:6–9).

In our system of thought, man came about as the direct and purposeful creation of the loving God who has revealed Himself in the Bible (Genesis 2:7). Furthermore, man was assigned a specific and far-reaching duty by God on the very day he was created (Genesis 1:26–29). Man and his task must be understood in terms of the eternal God and His plan, rather than in terms of himself and an environment of chance and change.

Non-Christian secularist thought destroys the meaning and significance of man by positing that he is nothing more than a chance fluke, an accidental collection of molecules arising out of the slime and primordial ooze. Man is a frail speck of dust caught up in a gigantic, impersonal, multi-billion-year-old universe. That, and nothing more.

The famous 20th-century atheist Bertrand Russell put it well when he wrote:

The world is purposeless, void of meaning. Man is the outcome of accidental collocations of atoms; all the devotion, all the inspiration, all the noonday brightness of human genius are destined to extinction in the vast death of the solar system. Only on the firm foundation of unyielding despair can the soul’s habitation be safely built. From evolution no ultimately optimistic philosophy can be validly inferred.3


To the question concerning which system is the most adequate for explaining external reality, the possibility of knowledge, a relevant and binding ethic, and the significance of man, the answer should be obvious: only the worldview presupposing the truth claims of the Bible is sufficient for the task.

Actually, the defense of Christianity is simple: we argue the impossibility of the contrary. Ironically, those who assault the Christian system must actually assume the Christian system to do so. That is, they must assume a rational world for which only Christianity can account. In fact, atheism assumes theism. If the God of Scripture did not exist, there would be no man in any real world to argue—there would be no possibility of rationality by which an argument could be forged, and there would be no purpose in debate! Charles Darwin stated this problem in his personal letter to W. Graham on July 3, 1881:

But then with me the horrid doubt always arises whether the convictions of man’s mind, which has always been developed from the mind of the lower animals, are of any value or at all trustworthy. Would any one trust in the convictions of a monkey’s mind, if there are any convictions in such a mind?4

Paul spoke powerfully when he declared in Romans 3:4, “Let God be true but every man a liar” (KJV).

The God of Scripture, the Father of our Lord Jesus Christ, is the ultimate and necessary foundation for a rational, coherent worldview. Every other system is built upon a lie—the fallible ideas of sinful and rebellious man. The Christian system begins with: “In the beginning God. . . .” And from that foundational reality, all the rest of a rational worldview falls into place.

World Religions and Cults Volume 1

In many of cases, manmade religions openly affirm that the Bible is true, but then something gets in their way. The common factor: man’s fallible opinions!

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  1. Thomas Kuhn, The Structure of Scientific Revolutions (Chicago, IL: University of Chicago Press, 1962).
  2. Cornelius Van Til, The Defense of the Faith (Philipsburg, NJ: P & R Publishing, 1972), p. 102.
  3. Bertrand Russell, Mysticism and Logic (New York: Doubleday, 1917), p. 45–46.


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