Reasons to Believe
Six Arguments for the Truth of Christianity
A careful examination of the philosophical, historical, and scientific evidence — for the honest seeker, the thoughtful skeptic, and the believer who wants to go deeper.
Christianity does not ask for blind faith. It invites rigorous examination. The following arguments represent the best philosophical and historical case for the existence of God and the truth of Christianity — drawn from centuries of careful theological and philosophical reflection.
I
THE COSMOLOGICAL ARGUMENT
KALAM · FIRST CAUSE · CONTINGENCY
The cosmological argument asks a deceptively simple question: why is there something rather than nothing? The universe exists. It had a beginning. Everything that begins to exist has a cause. What caused the universe?
The Kalam Cosmological Argument, championed by philosopher William Lane Craig, presents this syllogism with renewed force using modern cosmology:
The Argument
P1 Whatever begins to exist has a cause
P2 The universe began to exist
∴ Therefore, the universe has a cause
Modern cosmology has strengthened this argument considerably. The Big Bang model — supported by the expansion of the universe, background radiation, and thermodynamic reasoning — establishes that the universe had an absolute beginning. Space, time, matter, and energy all came into existence at a finite point in the past.
The cause of the universe must therefore be uncaused (or it would need its own cause), timeless (since time began with the universe), spaceless, immaterial, enormously powerful, and — to produce a universe from nothing — must be a personal agent capable of willing creation. This description maps remarkably well onto the God of classical theism.
Common Objection
“The universe could be eternal, or could have come from a quantum vacuum — no cause needed.”
Response
The Borde-Guth-Vilenkin theorem (2003) established that any universe that has been on average expanding throughout its history must have a beginning — including multiverse models. A quantum vacuum is not “nothing” — it is a quantum field with laws and properties that themselves require explanation. The regress always terminates at something uncaused.
“In the beginning, God created the heavens and the earth.”
— Genesis 1:1
II
The Fine-Tuning Argument
TELEOLOGICAL · COSMOLOGICAL CONSTANTS · DESIGN
The universe appears to be calibrated for life with extraordinary precision. The physical constants and quantities of nature — the strength of gravity, the cosmological constant, the mass of the electron, the ratio of electromagnetism to gravity — are set to values that permit the existence of life within astonishingly narrow margins.
Physicist Paul Davies has estimated that if the expansion rate of the universe one second after the Big Bang had been smaller by even one part in 1055, the universe would have collapsed back on itself. If it had been larger by the same amount, no galaxies, stars, or planets would have formed. The cosmological constant is fine-tuned to 1 part in 10120. These are not small tolerances.
There are three possible explanations for this fine-tuning: physical necessity (the constants had to be these values — but physicists know of no reason they should), chance (possible, but the probabilities are vanishingly small, even across multiverse models), or design (a mind calibrated the universe for life). The design hypothesis, while not provable in isolation, provides the most natural and intellectually satisfying explanation.
Lorem ipsum dolor sit amet, consectetur adipiscing elit. Ut elit tellus, luctus nec ullamcorper mattis, pulvinar dapibus leo.
Common Objection
“The multiverse explains fine-tuning — if there are infinitely many universes, we’d inevitably find ourselves in a life-permitting one.”
Response
The multiverse is itself an unobserved, speculative hypothesis requiring fine-tuned conditions for multiverse generation (a “universe-generating mechanism” that itself requires explanation). Even granting a multiverse, it explains physical fine-tuning but does not address the fine-tuning of laws of logic, mathematical structures, or consciousness. It also does not eliminate design as an explanation — a multiverse generator could itself be designed.
III
The Resurrection of Jesus
HISTORICAL · EVIDENTIAL · MINIMAL FACTS
The resurrection of Jesus Christ is the cornerstone of Christian faith — and the most historically examined event in antiquity. Historian Gary Habermas has documented that there are four facts about the fate of Jesus that are so well-attested that they are accepted by the vast majority of historical scholars, including those who are not Christians:
The Minimal Facts (accepted by critical scholars)
P1 Jesus died by crucifixion under Pontius Pilate
P2 His tomb was found empty on the third day
P3 His disciples sincerely believed they had seen him alive after death
P4 Paul and James — a skeptic and a persecutor — experienced appearances and converted
∴ The resurrection is the best historical explanation of these facts
The early creed in 1 Corinthians 15:3–7 — which most scholars date to within 3–5 years of the crucifixion — lists eyewitness appearances to more than 500 people at once. The disciples’ willingness to die for their testimony distinguishes their claim from ordinary religious belief — people die for what they believe, but rarely for what they know to be a deliberate fabrication.
Common Objection
“The disciples were hallucinating, or the legend grew gradually over centuries.”
Response
Mass hallucinations of the same specific content are not documented in psychological literature. The creed in 1 Corinthians 15 predates legend formation — it circulates within the lifetime of eyewitnesses who could be interrogated. The conversion of James (Jesus’ skeptical brother) and Paul (an active persecutor) requires a specific, powerful experience — not legend — to explain. The empty tomb requires a physical explanation that hallucination cannot provide.
“And if Christ has not been raised, your faith is futile and you are still in your sins. But in fact Christ has been raised from the dead.”
— 1 Corinthians 15:17, 20
IV
The Moral Argument
ETHICS · MORAL REALISM · TRANSCENDENT LAWGIVER
We all act as though some things are genuinely wrong — not just culturally inconvenient, not merely personally distasteful, but objectively, really wrong. Torturing children for entertainment is not just something we happen to dislike. It is wrong. But if the universe is purely physical — matter, energy, space, and time — where do objective moral facts come from? Physical particles carry no moral weight.
The Argument
P1 If God does not exist, objective moral values and duties do not exist
P2Objective moral values and duties do exist
∴ Therefore, God exists
The premise that objective moral values exist is known immediately and intuitively by virtually every human being. The Holocaust was not merely “different” from what the Allies preferred — it was evil. This intuition is so powerful and so universal that denying it costs more than the alternative: affirming that objective moral values exist and require a grounding in a transcendent moral reality — which Christians identify as God.
Common Objection
“Evolution explains morality — moral instincts are survival mechanisms selected by natural selection.”
Response
Evolution might explain why we have moral feelings — but it cannot explain why those feelings correspond to objective moral facts. If evolution produced our moral sense, it produced it for survival, not truth-tracking. A moral sense that evolved for reproductive success gives us no reason to think that what “feels” wrong is actually wrong — it only tells us what our ancestors’ genes found advantageous. This is a debunking argument against naturalist ethics, not a vindication of it.
V
The Reliability of Scripture
TEXTUAL CRITICISM · PROPHECY · HISTORICAL ATTESTATION
The Bible is the most textually attested document from the ancient world. For comparison: Caesar’s Gallic Wars is known from 10 manuscripts, the earliest copied 1,000 years after Caesar’s death. The New Testament is known from over 5,800 Greek manuscripts, with portions dating to within decades of the original writing. No other ancient document comes close.
Textual scholar Bruce Metzger — no conservative evangelical — concluded that the New Testament text is 99.5% certain, with no major doctrine in question from the variants that do exist. The historical framework of the New Testament has been consistently confirmed by archaeology, geography, and extrabiblical sources including Josephus, Tacitus, and Pliny.
The prophetic evidence is equally striking. Isaiah 53 — written 700 years before Christ, confirmed by the Dead Sea Scrolls to predate the Christian era — describes a suffering servant who is despised, rejected, pierced for our transgressions, and whose soul is made an offering for sin. Psalm 22, written by David approximately 1,000 BC, describes crucifixion before it was invented as a method of execution.
Common Objection
“Evolution explains morality — moral instincts are survival mechanisms selected by natural selection.”
Response
The Gospels were written within the lifetime of eyewitnesses — within 40 years of the events for the earliest (Mark, c. 55–65 AD). The gap between the autograph and our earliest manuscripts is far smaller than for any comparable ancient document. Bias does not disqualify a source — every historian has a perspective. The question is whether the sources are reliable, and the criteria of embarrassment, multiple attestation, and enemy attestation all support the reliability of the Gospel accounts.
VI
The Argument from Consciousness
HARD PROBLEM · MIND-BODY · PERSONAL EXPLANATION
The “hard problem of consciousness” — philosopher David Chalmers’ term — is the problem of explaining why there is subjective experience at all. Why does it feel like something to see red, to hear music, to feel pain? Physical descriptions of neural processes describe the mechanics — they do not explain the experience. The brain produces brain states. Consciousness produces experience. These are two entirely different kinds of thing.
A purely physical universe — one consisting only of matter, energy, and impersonal forces — has no room for consciousness. Particles have no inner life. Atoms have no experience. If the universe is simply a closed physical system, consciousness is either an illusion (which is self-refuting — who is experiencing the illusion?) or an emergent property of physical complexity (but no one has explained how physical complexity produces the felt quality of experience).
The existence of consciousness — the fact that the universe contains beings who experience it from the inside — is naturally explained by a universe created by and for personal beings. A God who is himself personal, who created personal beings in his image, makes sense of consciousness in a way that pure materialism cannot.
Common Objection
“We will eventually explain consciousness scientifically — we just haven’t done it yet.”
Response
The hard problem is not a gap in scientific knowledge that will eventually be filled — it is a conceptual problem about the relationship between the physical and the experiential. No advance in neuroscience explains why neural correlates of consciousness should be accompanied by any experience at all. Philosopher Thomas Nagel — an atheist — wrote that “consciousness is the most serious challenge to a materialistic view of the world,” and that the standard scientific approach “cannot in principle explain the subjective character of experience.”
The Cumulative Case
No Single Argument — But a Convergence
None of these arguments, taken individually, constitutes a deductive proof of Christianity. But taken together — cosmological, teleological, historical, moral, textual, and phenomenological evidence all converging on the same conclusion — the cumulative case for the existence of God and the truth of Christianity is formidable.