Here’s the peer-reviewed article. It appears in a scientific journal focused on astrophysics.

Here’s the abstract:

Both cosmology and philosophy trace their roots to the wonder felt by the ancient Greeks as they contemplated the universe. The ultimate question remains why the universe exists rather than nothing. This question led Leibniz to postulate the existence of a metaphysically necessary being, which he identified as God. Leibniz’s critics, however, disputed this identification, claiming that the space-time universe itself may be the metaphysically necessary being. The discovery during this century that the universe began to exist, however, calls into question the universe’s status as metaphysically necessary, since any necessary being must be eternal in its existence. Although various cosmogonic models claiming to avert the beginning of the universe predicted by the standard model have been and continue to be offered, no model involving an eternal universe has proved as plausible as the standard model. Unless we are to assert that the universe simply sprang into being uncaused out of nothing, we are thus led to Leibniz’s conclusion. Several objections to inferring a supernatural cause of the origin of the universe are considered and found to be unsound.

The whole text of the article is posted online here.

Here’s an excerpt in which the author, Dr. William Lane Craig, explains the Big Bang cosmology:

The monumental significance of the Friedman-Lemaitre model lay in its historization of the universe. As one commentator has remarked, up to this time the idea of the expansion of the universe “was absolutely beyond comprehension. Throughout all of human history the universe was regarded as fixed and immutable and the idea that it might actually be changing was inconceivable.”{8} But if the Friedman-Lemaitre model were correct, the universe could no longer be adequately treated as a static entity existing, in effect, timelessly. Rather the universe has a history, and time will not be matter of indifference for our investigation of the cosmos. In 1929 Edwin Hubble’s measurements of the red-shift in the optical spectra of light from distant galaxies,{9} which was taken to indicate a universal recessional motion of the light sources in the line of sight, provided a dramatic verification of the Friedman-Lemaitre model. Incredibly, what Hubble had discovered was the isotropic expansion of the universe predicted by Friedman and Lemaitre. It marked a veritable turning point in the history of science. “Of all the great predictions that science has ever made over the centuries,” exclaims John Wheeler, “was there ever one greater than this, to predict, and predict correctly, and predict against all expectation a phenomenon so fantastic as the expansion of the universe?”{10}

As a GTR-based theory, the Friedman-Lemaitre model does not describe the expansion of the material content of the universe into a pre-existing, empty, Newtonian space, but rather the expansion of space itself. This has the astonishing implication that as one reverses the expansion and extrapolates back in time, space-time curvature becomes progressively greater until one finally arrives at a singular state at which space-time curvature becomes infinite. This state therefore constitutes an edge or boundary to space-time itself. P. C. W. Davies comments,

An initial cosmological singularity . . . forms a past temporal extremity to the universe. We cannot continue physical reasoning, or even the concept of spacetime, through such an extremity. . . . On this view the big bang represents the creation event; the creation not only of all the matter and energy in the universe, but also of spacetime itself.{11}

The popular expression “Big Bang,” originally a derisive term coined by Fred Hoyle to characterize the beginning of the universe predicted by the Friedman-Lemaitre model, is thus potentially misleading, since the expansion cannot be visualized from the outside (there being no “outside,” just as there is no “before” with respect to the Big Bang).{12}

The standard Big Bang model thus describes a universe which is not eternal in the past, but which came into being a finite time ago. Moreover,–and this deserves underscoring–the origin it posits is an absolute origin ex nihilo. For not only all matter and energy, but space and time themselves come into being at the initial cosmological singularity. As Barrow and Tipler emphasize, “At this singularity, space and time came into existence; literally nothing existed before the singularity, so, if the Universe originated at such a singularity, we would truly have a creation ex nihilo.“{13}

[…]On such a model the universe originates ex nihilo in the sense that at the initial singularity it is true that There is no earlier space-time point or it is false that Something existed prior to the singularity.

Every theist should be able to understand and defend this argument. It is a scientific refutation of materialism, and it is supported by six lines of scientific evidence – all of which emerged as science has progressed.

Scientific evidence:

1. Einstein’s theory of general relativity (GTR)
2. the red-shifting of light from distant galaxies implies an expanding universe
3. the cosmic background radiation (which also disproves the oscillating model of the universe)
4. the second law of thermodynamics applied to star formation theory
5. hydrogen-helium abundance predictions
6. radioactive element abundance predictions

Those are the scientific discoveries that have led us to the beginning of the universe, which support’s Dr. Craig’s argument.

Here’s a re-cap of the three main evidences for the Big Bang cosmology from Caltech. (Numbers 2, 3 and 5 from the list above)

Excerpt:

Until the early 1900s, most people had assumed that the universe was fixed in size. New possibilities opened up in 1915, when Einstein formulated his famous general relativity theory that describes the nature of space, time, and gravity. This theory allows for expansion or contraction of the fabric of space. In 1917, astronomer Willem de Sitter applied this theory to the entire universe and boldly went on to show that the universe could be expanding. Aleksandr Friedmann, a mathematician, reached the same conclusion in a more general way in 1922, as did Georges Lemaître, a cosmologist and a Jesuit, in 1927. This step was revolutionary since the accepted view at the time was that the universe was static in size. Tracing back this expanding universe, Lemaître imagined all matter initially contained in a tiny universe and then exploding. These thoughts introduced amazing new possibilities for the universe, but were independent of observation at that time.

Why Do We Think the Big Bang Happened?

Three main observational results over the past century led astronomers to become certain that the universe began with the big bang. First, they found out that the universe is expanding—meaning that the separations between galaxies are becoming larger and larger. This led them to deduce that everything used to be extremely close together before some kind of explosion. Second, the big bang perfectly explains the abundance of helium and other nuclei like deuterium (an isotope of hydrogen) in the universe. A hot, dense, and expanding environment at the beginning could produce these nuclei in the abundance we observe today. Third, astronomers could actually observe the cosmic background radiation—the afterglow of the explosion—from every direction in the universe. This last evidence so conclusively confirmed the theory of the universe’s beginning that Stephen Hawking said, “It is the discovery of the century, if not of all time.”

The article goes into detail about each of these three evidences.

This is the kind of evidence I expect all Christian theists to be using when discussing the question of whether God exists. Scientific evidence. When talking to non-Christians, we first need to show that we understand science, because science is a reliable and respected way of getting knowledge about the universe. Non-Christians do not accept the Bible, but they do accept science, so we begin evangelism with science. Science (experimental, testable, repeatable science) should set limits on what anyone can believe – including non-Christians, who might otherwise not be inclined to listen to Bible verses and theology.

The Big Bang is not compatible with atheism

According to the Secular Humanist Manifesto, atheism is committed to an eternally existing universe, (See the first item: “Religious humanists regard the universe as self-existing and not created.”). If something non-material brought all existing matter into being, that would be a supernatural cause, and atheists deny that anything supernatural exists. The standard Big Bang theory requires that all the matter in the universe come into being out of nothing. This falsifies eternal models of the universe, which are required by the atheistic worldview.

You should definitely print out both articles and get familiar with the arguments and the evidence. I have tried this argument out on atheists, and the response I usually get is that scientific discoveries will soon emerge that falsifies all of these six scientific discoveries. That sounds more like faith than reason to me. And we have to make it clear to others who are still deciding that there is a conflict between science and religion. Just not the one they’re expecting. Let’s make our decisions about what to believe based on what science is telling us today. Let’s hold accountable people who want to have a worldview that is based on speculations.