GC:engage - Does God Exist?


(Part 1: Becoming An Effective Ambassador For Christ)

Christian theologians often cite three classic reasons for believing the Christian God exists. Theologians do not claim that these arguments lead to final, complete truth, only that their cumulative impact (through the use of abductive reasoning) presents a reasonable, compelling case for God’s existence.

1) The Cosmological Argument

Why is there something rather than nothing? Cosmological arguments have to do with the origin of the universe. Not the universe as in planets and stars, but the universe as in everything that is. It is often presented in this simple syllogistic style:

  • Everything that begins to exist has a cause
  • The universe began to exist
  • The universe has a cause

In short – something outside of the universe caused the universe. As Greg Koukl likes to say, “a big bang needs a big banger”.

2) The Moral Argument

What is the foundation of morality?  C.S. Lewis wrote one of the most well-known summaries:

   “My argument against God was that the universe seemed so cruel and unjust. But how had I got this idea of just and unjust? A man does not call a line crooked unless he has some idea of a straight line.” 

In a more formal syllogism, the argument takes this form:

  • If God does not exist, objective moral values and duties do not exist.
  • Objective moral values and duties do exist.
  • Therefore, God exists. 

3) The Teleological Argument

How does one explain the overwhelming impression of design? You may have heard the terms teleological argument, argument from design, or the fine-tuning argument. These have to do with the likelihood that anything exists, the likelihood that any life exists, or the likelihood that humans exist.

It seems incredibly unlikely – and perhaps impossible – that undirected processes would result in human life. Take an aquarium, for example. There is a range of acceptable salinity that is quite narrow. The same applies to light, temperature, food, air, size of tank, etc. The human living environment on earth and in the universe is almost unimaginably more complex: Gravity, temperature, nuclear forces, atmosphere around us, distance from sun and moon, ozone layer, existence of water, etc…. Roger Penrose, the Rouse Ball Professor of Mathematics at the University of Oxford, recently noted:

“The likelihood of the universe having usable energy (low entropy) at its creation is ‘one part out of ten to the power of ten to the power of 123.’ That is ‘a million billion billion billion billion billion billion billion billion billion billion billion billion billion.’”- as quoted in “Why Some Scientists Embrace the Multiverse,” by Dennis Prager

The syllogism looks like this:

  •   The universe appears to be designed (specified complexity).
  •   This happened either by chance, necessity, or design.
  •   Not chance or necessity.
  •   Therefore, it was designed.

 These arguments, as well as others Christian theologians have presented, have certainly not convinced everyone. Antony Flew* once raised a challenge in the form of a story called The Parable of the Gardener. Here is a version cited by Flew in “Theology and Justification”:

 "Once upon a time two explorers came upon a clearing in the jungle. In the clearing were growing many flowers and many weeds. One explorer says, “Some gardener must tend this plot.” So they pitch their tents and set a watch. No gardener is ever seen. “But perhaps he is an invisible gardener.” So they set up a barbed-wire fence. They electrify it. They patrol with bloodhounds. (For they remember how H. G. Wells’ The Invisible Man could be both smelt and touched though he could not be seen.) But no shrieks ever suggest that some intruder has received a shock. No movements of the wire ever betray an invisible climber. The bloodhounds never give cry. Yet still the Believer is not convinced. “But there is a gardener, invisible, intangible, insensible to electric shocks, a gardener who has no scent and makes no sound, a gardener who comes secretly to look after the garden which he loves.” At last the Skeptic despairs, “But what remains of your original assertion? Just how does what you call an invisible, intangible, eternally elusive gardener differ from an imaginary gardener or even from no gardener at all?” 

In response, John Frame wrote the following parable in “God and Biblical Language: Transcendence and Immanence”:

 Once upon a time two explorers came upon a clearing in the jungle. A man was there, pulling weeds, applying fertilizer, trimming branches. The man turned to the explorers and introduced himself as the royal gardener. One explorer shook his hand and exchanged pleasantries. The other ignored the gardener and turned away: “There can be no gardener in this part of the jungle,” he said; “this must be some trick. Someone is trying to discredit our previous findings.” They pitch camp. Every day the gardener arrives, tends the plot. Soon the plot is bursting with perfectly arranged blooms. “He’s only doing it because we’re here-to fool us into thinking this is a royal garden.” The gardener takes them to a royal palace, introduces the explorers to a score of officials who verify the gardener’s status. Then the skeptic tries a last resort: “Our senses are deceiving us. There is no gardener, no blooms, no palace, no officials. It’s still a hoax!” Finally the believer despairs: “But what remains of your original assertion? Just how does this mirage, as you call it, differ from a real gardener?”


*Antony Flew late became a Deist, citing design as a compelling reason to believe that God in some fashion existed. He never embraced the beliefs of any particular religion.



  1. Origins: “A Bigger Story”, Ravi Zacharias
  2. Cosmological Argument

               Chapter 3, Reasonable Faith, William Lane Craig

               Chapter 4, On Guard, William Lane Craig

               Chapter 1, The Questions Christians Hope No One Will Ask, Mark Mittelberg

                Chapter 5, Is God Just a Human Invention, Sean McDowell (Geivett)

                Blackwell Companion to Natural Theology, Craig & Moreland

                The Existence of God and the Beginning of the Universe, William Lane Craig

                Overview of the Cosmological Argument, William Lane Craig

                Cosmological Argument, William Lane Craig

                 Kalam Cosmological Argument, JP Moreland

                 The Thomist Cosmological Argument, Peter Kreeft

                 What is the Kalam Cosmological Argument?, Craig and Conway

          3. Moral Argument

                     True for You, but not for Me, Paul Copan

                      The Abolition of Man, C.S. Lewis

                      A Refutation of Moral Relativism, Peter Kreeft

                      Chapter 3, Reasonable Faith, William Lane Craig

                      Chapter 6, On Guard, William Lane Craig

                      Chapter 1, The Questions Christians Hope No One Will Ask, Mark Mittelberg

                      Chapter 15, Is God Just a Human Invention, Sean McDowell (Linville)

                      God, Naturalism and Morality, Paul Copan (in “The Future of Atheism”)

                      Why I Am Not a Moral Relativist, Francis Beckwith

                      The Moral Argument for God’s Existence, Paul Copan

                       Did Morals Evolve?, Greg Koukl

                       Debate: Is the Foundation of Morality Natural or Supernatural?, Craig/Harris

                       Why I’m Not an Atheist, Ravi Zacharias

                       Grounding Morality, Greg Koukl

                        What is the Moral Argument for the Existence of God?, Craig/Conway

          4. Teleological Argument

                          Natural Theology, William Paley

                          Signature in the Cell, Stephen Meyer

                          Chapter 4, Reasonable Faith, William Lane Craig

                          Chapter 5, On Guard, William Lane Craig

                          Chapter 1, The Questions Christians Hope No One Will Ask, Mark Mittelberg

                          Chapters 6-7, Is God Just a Human Invention, Sean McDowell (Rana, Richards)

                           Fine-Tuning For Life In The Universe, Hugh Ross

                           Dr. Stephen Meyer at Cambridge

                           Why is the Universe Fine-Tuned, Guillermo Gonzalez

                           Dr. Fuz Rana discusses the beauty and elegance of biochemistry

                           What is the Fine-Tuning Argument for the Existence of God?, Craig/Conway

       5. General Resources