Central to any argument about whether god exists or not is the notion of time and its relationship with being. "What is time?", is such a profound question that underlies our entire sense of reality. The fundamental nature of time is so puzzling that we do not get a consensus amongst physicists and philosophers alike on what its true properties are.
In philosophy, there are generally two theories on the nature of time, A-theory and B-theory. The A-theory of time states that the present is all that exists. The past no longer exists, and the future is a mere possibility, but doesn't yet exist. There is only the eternal now of the present moment. Because past and future do not exist, they aren't in a sense, real. The A-theory of time is adopted by most Christian theologians as describing the nature of time within Christian theology. Buddhism also interprets time according to the A-theory. The A-theory states that there is a "master time" or absolute time of which all clocks are set to, even if others tick slower of faster. Our intuitions are more closely in tune with the A-theory of time because we feel that we exist only in the present, and so the present is therefore all that exists.
The B-theory of time states however, that the past, present and future all exist and are therefore all equally real. The past doesn't cease to exist once it's gone and the future doesn't come into being when it is reached at the present moment. Think of it like driving down a road. The town up ahead doesn't begin to exist when you reach it, it already exists, you just haven't gotten to it yet. Under the B-theory of time, the future already exists, it has already happened in a sense, we just haven't gotten to it yet on our subjective journeys through time. This means that notions like the experience of the passage of time are subjective illusions, and indeed time itself is an illusion. Past, present and future are more like destinations that we can in theory, travel to. The B-theory of time runs counter-intuitive to how we generally sense our understanding of time.
Now what does physics say on the matter? Issac Newton's understanding of time as a fixed absolute would agree with the A-theory of time, but we now know that Newton was wrong on time for all his genius. Einstein's general theory of relativity helped close the gap in our knowledge on the true nature of time. Time and space are intertwined in what we now call space-time, and the laws of physics permit the passage of time to increase or decrease depending on your speed relative to other objects, and the strength of gravity where you are. The faster you move and the stronger gravity is around you, the slower time passes.
This has amazing implications on what we think of as "now". We generally believe that the present moment is the same for everyone and everything. While I'm typing this blog, you are currently doing something at the same time. My now is your now, and your now is my now. But general relativity tells us that that is not quite so. If another being living in some far off galaxy at the far reaches of the universe, say 13 billion light years away were to travel away from us at a certain speed, their "now" would actually be our past. And depending on how far or fast they were moving would depend on how far into our past their "now" would be. So their "now" could be a year ago or a thousand years ago before we were even born. If they started traveling towards us, their "now" would encompass our future, even after we might be dead. But you're thinking, "Wait a minute, the future hasn't happened yet. How could someone else's "now" be our future that hasn't yet happened?" I've pondered exactly this problem myself.
Physics therefore, has demonstrated that the B-theory of time is more compatible with its laws. Watch physicist Brian Green explains in the clip below from the Nova ScienceNow special, Fabric of the Cosmos: The Illusion of Time how this concept works.
Time is like a frozen river, and our experience of the present may just be a subjective illusion. What does this say about the existence of god? Well, the Kalaam Cosmological Argument, so often used by theists as the "shock and awe" tactic and front line of offense is predicated on the A-theory of time, which we now know not to be true. That doesn't mean that god is definitively disproven, but it punches serious holes in the argument that theists have to address.
This is where William Lane Craig enters since he is the current champion of the KCA. I've voiced my concerns over the problems of god and timelessness numerous times, particularly how a "timeless" and "changeless" being can have a causal relationship with temporal events, like creating a universe. Furthermore, if the beginning of the universe is the first event and thus the beginning of time, if god caused the universe to exist, then the cause of the universe would have to precede time. In other words, time would have to exist, before time existed. Logically, it's like saying I was born, before I was born.
I recently was reading a paper Craig wrote years ago about timelessness and creation in which he takes on these same concerns that were made by Oxford University Professor Brian Leftow. In it he writes:
God's choices are not events, since He neither deliberates temporally nor does His will move from a state of indecision to decision. He simply has free determinations of the will to execute certain actions, and any deliberation can only be said to be explanatorily, not temporally, prior to His decrees. If time is essential to choosing, then a timeless God could not choose between a beginningless or a finite time either.
It would seem according to Craig, that the execution of god's will must create time since he believes god is temporal posterior to the creation of the universe, which is an event. But how can god have "free determinations of the will" if he is timeless? In the paper Craig scrutinizes three theories that Leftow criticizes. I won't mention all of them, but the theory that Craig settles on, is one that states that time was preceded by what Craig calls "finite time". In other words, in order for god to have created the universe before time existed, and in order to explain god's timeless state before he somehow willed time into existence, another form of time had to exist before time existed. Craig argues:
Since t [the beginning of time] is preceded by finite time, that time is not the consequence of t's being the time of the first event (otherwise it would be infinite or amorphous, since if t's elapsing is itself sufficient that there should have been n finite time units prior to t, it would also be sufficient for there having been n+1 finite time units prior to t). So the times prior to t must be either substantival time units in their own right or the relational consequences of events going on prior to t. Thus, if God refrained from creating t, that would have no intrinsic effect on times prior to t; they would still have existed, only now they would be at the end of time. Thus, it is difficult to see how God could do anything at t to bring it about that time was infinite when it was in fact finite.
Basically Craig is saying finite time that existed before time cannot be infinite (hence the name) and must be some kind of "relational consequences of events going on prior to" time. But this doesn't make sense when Craig constantly stresses the absolute beginning of time at the Big Bang and according to his website says, "A sequence of mental events alone is sufficient to generate relations of earlier and later, wholly in the absence of any physical events." That sounds like regular time to me, and so it appears the theist might have to commit to the idea that time began before time began in order to make sense of the cosmological argument.
If theists can be expected to just make up imaginary units of time, as is the case with "finite time" existing before time on purely philosophical and theological grounds, with no scientific theories or hypotheses backing them up, then how can we be expected to have a serious debate? The atheist goes to great lengths to make his case as scientific as possible. That doesn't mean to say that a theist can't be knowledgeable of science and use it to make their case, but if they get to violate logic by resorting to theories that have no scientific basis, and in some cases are even refuted by science, like the A-theory of time, then they should at least stop making a big fuss when we say that the universe came into being without a prior cause. It's only fair.
Further reading on arguments against god:
The Kalam Cosmological Argument
The Fine Tuning Argument
Objective Morality Without God
Refuting William Lane Craig: "Is Good from God?" A Debate Review
Refuting William Lane Craig: The Moral Argument
The Logically Implausible God
The Logically Implausible God Part 2
The Ontological Argument: Putting the Absurd Where it Belongs