by Dima Zhyvov
Are there are any good arguments for God’s existence? Both Matt and I are convinced that there are, and in this series we intend to bring the various lines of reasoning to the conclusion that the Christian God exists. But before we do that, let us briefly discuss some important questions that are relevant to our aim.
What makes a good argument good?
When assessing whether the arguments for God’s existence that we propose are good or not, I think it is important to be clear just what it is that makes an argument for God, or in fact any argument at all, a good one. There seems to be several important criteria that one should be looking for in regards to this question.
First, there is a criterion of validity. When assessing whether any particular argument meets this criterion, we must ask, is the argument in question logically valid or not, or in other words, does the conclusion logically follow from the premises? If it does, then no matter how much we may dislike the conclusion, the premises in the argument, if true, guarantee the truth of its conclusion.
Second, one must look at whether an argument is sound or not. As was hinted above, valid logical inference alone is not enough to make for a good argument. Consider the following example:
(1) All birds can fly
(2) Penguins are birds
(3) Therefore, penguins can fly
How good is this argument? Does it pass the criterion of validity? Certainly! If (1) is true and (2) is true, then it logically follows that (3) must also be true. So what is wrong with it? Well, in short, the facts are wrong. It is simply not true that all birds can fly. So in the example above, we must note that although the argument is valid, at least one premise is false and hence the argument is unsound and must be rejected. So to sum up, a sound argument is such that contains all true premises and valid logical inference towards the conclusion.
Finally, there is something to be said about the argument’s persuasiveness. Suppose I come up with an argument that is valid and happens to have all true premises, but they are such that no one can know or judge whether they are true or not. In this case the argument will still be sound, but how useful is it to persuade someone? Why do we construct arguments in the first place? If we use arguments to rationally argue for some conclusion, then a sound argument whose premises are epistemically inaccessible to us is useless in that regard. Thus good arguments are valid arguments that contain premises which, in addition to being true, can also be estimated to be true by the one who assesses the argument.
It is at this point that the question of certainty comes in. When talking about good arguments for God’s existence I have purposely avoided the word “proof”. I find that the word “proof” conveys the need to provide some sort of infallible, mathematical proof (e.g. 1 + 1 = 2) for God’s existence.
In his book, Logic: An introduction, Lionel Ruby writes: “Every person who is interested in logical thinking accepts what we shall call the “law of rationality,” which may be stated as follows: We ought to justify our conclusions by adequate evidence…. By “adequate evidence” we mean evidence which is good and sufficient in terms of the kind of proof which is required. There are occasions when we require conclusive proof, as in mathematics, and there are occasions when it is sufficient to establish the probability of a given conclusion, as in weather prediction. But in all cases the evidence must be adequate to its purpose.” (1)
When we talk about good arguments for God’s existence is it really necessary to expect theists to be able to demonstrate God’s existence with mathematical certainty? Just think about various beliefs that lack such certainty and you will understand that this standard is simply untenable in most cases outside of some technical fields such as mathematics. It might come as a surprise to you, but your belief that you are reading these very words on your computer screen, for instance, cannot be proven with 100% certainty. Why? Because it is logically possible that you are in fact a brain in a vat being stimulated by some crazy scientist in a parallel universe who simulates the reality around you, sending signals to your brain that cause it to have experiences of reading this blog and contemplating on whether you are a brain in a vat. 
What this scenario shows is that one can come up with a large number of logically possible scenarios accounting for your experience of reading the text on the screen, and no matter how crazy and incredible they are, these scenarios cannot be shown with certainty to be logically impossible, and hence the belief that you are actually reading this blog right now cannot be shown to be 100% certain. However, the mere possibility of some crazy account for your experience can hardly compel you to believe it or undermine the rationality of your belief that you are in fact reading these lines right now. Similarly, when talking about arguments for God’s existence, one needs to ask whether we have what logician Ruby called “adequate evidence” as opposed to demanding “conclusive proof” as in mathematics and logic. Hence, in our exposition of various arguments for God’s existence, we do not claim that their premises are such that its truth can be ascertained with 100% certainty; rather we are claiming that these premises are at least more plausible than their negations or contradictions, and that assent to them is rational and warranted.
Cumulative case for God’s existence
Lastly, I want to say a few words about the approach Matt and I chose to take in this series. In arguing for the existence of God we employ what is called a cumulative case method. The cumulative case method is an informal argument that pieces together several lines or types of data into a sort of hypothesis or theory that comprehensively explains that body of data and does so better than any alternative hypothesis. As Paul Feinberg points out, by arguing in this way “Christian theists are urging that Christianity makes better sense of all the evidence available than does any other hypothesis, whether that alternative is some other theistic view or atheism”. This is a significant point, because when we will discuss some particular argument for God’s existence, we are not claiming that this argument alone establishes the existence of a Trinitarian Christian God with all the attributes pertaining to his nature. Rather just like a lawyer in court presents his case, we will examine various strings of data such as the existence and nature of the cosmos, the objectivity of morality, the reality of religious experience, certain historical facts, and so on and seek to best explain it by proposing a hypothesis that the Christian God exists.
Without delaying you any longer let us now delve into the very arguments of our case for God’s existence.
The Argument from Jesus’ Resurrection
(1) See Lionel Ruby, Logic: An Introduction (Chicago, IL: J.B. Lippincott, 1960).
Warranted Belief 