First, we should probably clarify what we are talking about.
Definition of Terms
The God we are discussing is not just some vague, mystical notion of spirituality. God is the uncaused Cause, who has always existed. He is the uncreated Creator of all things. He is the independent Necessary Being on whom all of reality is grounded. God is not just great and powerful, he is the Greatest Conceivable Being. And specifically the God of Christianity has these attributes (and more):
is omnipotent (all powerful)
is omniscient (all knowing)
is omnipresent (present everywhere)
is the Creator of everything without being part of it
is the perfect balance of Justice and Love and the source of morality
This God has revealed himself to us.
Proof can be a little subjective, since individuals may hold differences of opinion about what is considered to be "sufficient" proof. In fact, often emotions and bad life experiences may hold more weight for them than rational arguments and objective facts. A good way to address this topic is using the best explanation approach, sometimes called abductive reasoning. Abductive reasoning, also known as inference to the best explanation, is often used by researchers or detectives during investigations. In this post, the cumulative case for God's existence will be introduced and examined. In the end, our search for truth leads us to look for the best explanation of all the evidence. Explanations which are coherent and consistent with the evidence should be given more credence.
Challenges
Over the centuries, many objections have been raised against the existence of God, or even any gods at all. The claim is made that there is no supernatural spiritual reality, and that only the physical world exists. Rather than spending a lot of time trying to understand motivations, let's take a look at some of the common objections.
There is no evidence for God. Prove it!
We don’t need God to explain everything, since science has discovered the answers (i.e. God of the Gaps).
Why is there so much evil? (i.e the Problem of Evil)
“The Cosmos is all that is or was or ever will be.” Carl Sagan
A Universe From Nothing – book by Physicist Lawrence Krauss
“Darwin made it easy to become an intellectually fulfilled atheist.” Richard Dawkins in The Blind Watchmaker
What's the big deal, I just believe in one less God than you?
Did God create us or did we create God?
While we can't address all of these in depth here, as we go we'll cover many of these objections as we look at some of the best arguments for the existence of God. (And, "Yes", all of these objections, and more, have been thoroughly addressed by Christians over the centuries.)
Troubles With Naturalism/Atheism
It has no adequate explanation for:
Origin of the Universe from Nothing (“no thing”)
Origin of Life from Non-Life (information and biological complexity)
Origin of the Mind from Non-thinking nature (consciousness, rationality, personhood)
Origin of objective morality vs. determinism and/or relativism
Apparent order and design in the universe for human life (Anthropic Principle)
Why life has ultimate meaning and purpose
Why each person has value, dignity, and worth
The life, claims, character, and resurrection of Jesus Christ
In fact, a book by prominent non-theist philosopher, Thomas Nagel, "Mind and Cosmos, Why the Materialist neo-Darwinian conception of nature is almost certainly false, makes the case that, philosophically, materialism is virtually indefensible.
Arguments for God's existence
Christian thinkers (and others) have studied this important question for centuries and have proposed many ways to make the case for the existence of God. Our view of whether or not God exists affects what we see as
real, true, right, valuable, and meaningful.
One point to be made is that not all arguments make a full case specifically for the God of the Bible, as most address some of the various attributes and characteristics of God, but not all. However, as a whole, they point to a being that matches the Christian God revealed in scripture.
Also, this is just a short summary of these arguments. I'll include some resources below for your personal research and interests. It is important to understand that none of the arguments against God are actually new, and they have been adequately addressed and refuted by learning and scholarly men, both past and present. So don't be dismayed when you hear atheistic arguments, and certainly don't accept them at face value. There are good answers, if you are willing to look, read, and study.
Some of these arguments include:
The Teleological (design) argument
The Moral argument
The Ontological argument
The Cosmological (Kalam) Argument
The case for the supernatural resurrection
Fulfilled biblical prophecies
One interesting way to view the universe is as God's Crime Scene (detective J.Warne Wallace). His book details 8 pieces of evidence and he asks if they can be explained by staying inside the room of the universe, or if it requires an intruder from outside the universe for the best explanation.
Cosmological Evidence
Biological Evidence
Mental Evidence
Nonmaterial consciousness emerged from unconscious matter
As humans, we are "free agents" in our otherwise "cause and effect" universe
Moral Evidence
Transcendent, objective moral truths exist in our universe
Evil and injustice continue to persist, in spite of our best efforts
The most important thing to remember is that we are looking for the overall "Best Explanation" for all our experiences and evidences. Below we'll look at some of these arguments.
The Cosmological Argument
This argument was proposed by Islamic theologians, and it goes like this:
Everything that begins to exist must have a (transcendent) Cause.
The universe began to exist.
Therefore, the Universe had a Cause.
Most recently this has been refined and promoted by Christian philosopher, WIlliam Lane Craig.
Philosophers understand that there cannot be an actual unending chain of causal events into the distant past, known as the problem of infinite regress. We must have the first Uncaused Cause → Cause → Causes … Virtually all the scientific models to date agree that the universe had a beginning sometime in the finite past (e.g. big bang models). This includes inflationary, multiverse models, so there is no escaping the conclusion that there was a beginning to all realistically possible universes, including ours. As this argument shows, a beginning requires a Beginner. (Or "A Big Bang requires a Big Banger!")
A Cumulative Case for a Beginning
Philosophical - "Nothing comes from Nothing" and the impossibility of actual infinities (infinite regress).
Theoretical - General Relativity predicts an expanding universe, which implies a beginning.
Observational - The universe is seen to be expanding away from us. Farther objects are moving away faster (red-shifts). Galaxies appear closer together the farther away they are (earlier in time).
Thermal - The universe has not yet run down (entropy or 2nd Law of Thermodynamics), so it can't be infinitely old.
Quantitative - Hydrogen vs. Helium abundance created in the first moments of the universe could only happen in hot, dense conditions. Short-lived radioactive isotopes are rare or missing, but those with longer half-lives are still around.
Residual - The cosmic background radiation, as measured by COBE and Planck, shows the expected temperature if the universe has expanded to its current size from a very hot, small size.
What is the best explanation for all of this evidence?
What Does the Bible Say About Origins?
"In the beginning, God created the Heavens and the Earth" Gen 1:1 - this includes all space, matter, energy, and time
All things were created in Him, through Him, for Him. He was before them, and they all hold together in Him - Col. 1:16-17
Before Time began - 2 Tim 1:9, Tit 1:2
All things that were made were made through Him - John 1:1-3
Created from things that cannot be detected/seen - Heb 11:3
God made and preserves the heavens and earth, and all they contain - Neh 9:6
"Do you know the ordinances of the heavens? Can you establish their rule on the earth?" Job 38:33 - rhetorical, implies God does
Summary on Origins
The Universe had a beginning of space, matter, energy, and time
A Beginning requires a Beginner --- A Big Bang requires a Big Banger!
Multiple pieces of evidence point to God as the Creator of the Universe
The Bible's description of the Beginning matches observation
The Best Explanation is not Naturalism or Pantheism, but God
The Teleological / Design Argument
The appearance of design in our world is undeniable to anyone that has looked at the wonders of our world. In Greek, “telos” means end. The teleological argument (design argument) means that there was an “end” (or purpose) in mind. Of course, the source of the design, whether it is only apparent or actual, is at the root of the debate. This argument goes as follows:
The appearance of design and fine-tuning in the universe, solar system, earth/moon, life,… is undeniable!
All our shared experience tells us that anything that is designed requires a Designer.
Given all of the examples of complex, interdependent designs that we see, it is reasonable to assume that they did not all arise by chance or necessity.
Therefore, it is reasonable to conclude that there had to be a Designer.
This has been also called the Watchmaker argument. A couple well-known examples are the construction and functional parts of the bacterial flagellum and the functioning of biological machinery in cells.
But Why Is There This Fine-Tuning?
Is it Chance, Necessity, or Design?
Chance - We just got lucky! Many appeal to multiverse trial and error, but really just pushes the required fine-tuning into the multiverse generator.
Necessity - The laws of physics had to be what they are. "Maybe one day we'll discover a theory that says why" (i.e. Science of the Gaps). The laws of physics don't determine these values, thus it is very likely a randomly constructed universe would be uninhabitable.
Design - Could it actually be designed by an outside intelligence? Is it reasonable to believe that life retroactively influenced/designed itself through QM and retrocausality, as some have tried to argue?
Here are a couple of good videos on Fine Tuning.
The Anthropic Principle
The anthropic principle says that the universe appears designed for the sake of human life. Observations show that the universe and its components have fine-tuned characteristics that make (intelligent) life possible, from the Big Bang → creation of the elements → galaxies → Milky Way → our Sun → Solar System → Planets → Earth/Moon → Biology of Life → Conscious humans. This is widely acknowledged by a variety of scientists:
"... humanity's existence places severe constraints on the physical constants, structure and history of the universe, the Milky Way Galaxy, the solar system, Earth and Earth's life." Hugh Ross, Improbable Planet
Freeman Dyson, theoretical physicist, "The more I examine the universe and study the details of its architecture, the more evidence I find that the universe in some sense knew we were coming"
Anthony Flew declared in There is a God: How the World’s Most Notorious Atheist Changed His Mind, that "the laws of nature seem to have been crafted so as to move the universe towards the emergence and sustenance of life"
"The chance," says Francis Collins, head of the human genome project, "that all these constants would take on the values necessary to result in a stable universe capable of sustaining complex life forms is almost infinitesimal. And yet those are exactly the parameters we observe."
"It would be very difficult to explain why the universe should have begun in just this way, except as the act of a God who intended to create beings like us" - physicist Stephen Hawking, A Brief History of Time
"A common sense interpretation of the facts suggests that a superintellect monkeyed with physics . . . and that there are no blind forces worth speaking about in nature. The numbers one calculates from the facts seem to me so overwhelming as to put this conclusion almost beyond question." - Fred Hoyle, Astronomer
The Moral Argument
All people and civilizations have recognized that some actions are right and others are wrong. This appears to be a part of our moral experience and intuition. Based on this common experience, it is argued:
All people recognize some form of moral code – that some things are Right and others are Wrong.
The existence of Right/Wrong implies a higher standard or law exists.
That higher law requires a Lawgiver.
Because the Moral Law transcends humanity, a transcendent lawgiver is required.
Put another way:
If God does not exist, objective moral values and duties do not exist.
But objective moral virtues and duties do exist.
Therefore, God exists.
Here is a good summary of some of the arguments, including the moral.
The Ontological Argument
This argument is based solely on reason, first proposed by Anselm in the 11th century. It is a little hard to fully grasp, since it is an a priori argument based on philosophy and reason alone. William Lane Craig makes a good presentation of philosopher Alvin Plantinga's version.
This is a paraphrased version of it:
In an infinity of possible worlds, a being with Maximum Greatness (Omnipotent, Omniscient, …) must exist in at least one of those worlds.
If that being exists in at least one world, then to be Maximally Great, it must exist in all.
Therefore, a being of Maximum Greatness (God) must exist.
Why the Existence of God Matters
We must believe God exists to be able to seek/please Him (Hebrews 11:6)
We are His chosen witnesses that He is the One God (Isaiah 43:10)
Because God loved us, He sent Jesus to save those who believe (John 3:16-18)
"You believe that there is one God. Good! Even the demons believe that—and shudder." (James 2:19)
The fool says in his heart, "There is no God." (Psalm 14:1-2)
Takeaways
Given all of the arguments and evidence, it is reasonable to believe in the existence of God as the Best Explanation for the Universe that we live in and experience.
Given the weight of the evidence, is it possible God does NOT exist? Yes, but is it reasonable? Where else in your life do you apply this same level of skepticism?
If there is a God, what does He want from us? If Jesus is the best explanation/evidence of who God is, then what would that mean for you?
Recommended Resources
God's Crime Scene, A Cold-Case Detective Examines the Evidence for a Divinely Created Universe, J. Warner Wallace
Improbable Planet, Hugh Ross, Reasons to Believe
Reasons to Believe (RTB) - Fine-Tuning Compendium reasons.org/fine-tuning
Creator and the Cosmos, Hugh Ross, Reasons to Believe
Why the Universe is the Way it is, Hugh Ross, Reasons to Believe
