This is a fairly good description of the so-called Horizon Problem in cosmology. The solution, as supported by a variety of lines of evidence is the notion that there was a period of very rapid expansion early on. This would have been mediated by a massive scalar particle similar in some ways to the Higgs Boson. We have evidence of this expansion in the variations in the cosmic microwave background radiation. While there was a suggestion of a 'smoking gun' in the form of B-mode vibrations in that background, the evidence seems to be controversial because of issues related to near source 'static'.<quoted text>
Why is the universe so uniform on a large scale? Why does it look the same at all points of space and in all directions? In particular, why is the temperature of the microwave back-ground radiation so nearly the same when we look in different directions? It is a bit like asking a number of students an exam question. If they all give exactly the same answer, you can be pretty sure they have communicated with each other. Yet, in that analogy above, there would not have been time since the big bang for light to get from one distant region to another, even though the regions were close together in the early universe. According to the theory of relativity, if light cannot get from one region to another, no other information can. So there would be no way in which different regions in the early universe could have come to have the same temperature as each other, unless for some unexplained reason they happened to start out with the same temperature.
Why did the universe start out with so nearly the critical rate of expansion that separates models that re-collapse from those that go on expanding forever, that even now, ten thousand million years later, it is still expanding at nearly the critical rate? If the rate of expansion one second after the big bang had been smaller by even one part in a hundred thousand million million, the universe would have re-collapsed before it ever reached its present size.
Despite the fact that the universe is so uniform and homogeneous on a large scale, it contains local irregularities, such as stars and galaxies. These are thought to have developed from small differences in the density of the early universe from one region to another. What was the origin of these density fluctuations?
The general theory of relativity, on its own, cannot explain these features or answer these questions because of its prediction that the universe started off with infinite density at the big bang singularity. At the singularity, general relativity and all other physical laws would break down: one couldn’t predict what would come out of the singularity. This means that one might as well cut the big bang, and any events before it, out of the theory, because they can have no effect on what we observe. Space-time would have a boundary – a beginning at the big bang. Science seems to have uncovered a set of laws that, within the limits set by the uncertainty principle, tell us how the universe will develop with time, if we know its state at any one time.
In any case, no invocation of a deity is required. And your sources are about 40 years out of date.