Of course, Jastrow's comment is exaggerated at best; theologians hardly predicted the Big Bang. If our universe turns out to be closed, hence with an end, this does not mean apocalyptic visions of the end of the world were on target. And even if a beginning for the universe is a successful prediction of one version of theism, this is still not that impressive. After all, even a stopped clock is right twice a day. The Big Bang becomes strong support for God only with an argument showing that such a beginning requires a Creator.

Creation out of absolute nothing is a metaphysical quagmire for theists anyway, since nothing must at least have the potentiality for becoming something. Since theists are stuck with potentiality, it might as well be something like a quantum vacuum.

Physicists use 'God' as a metaphor more often than other scientists-- especially in popular writing, but in the technical literature as well. Of course, this is just a metaphor for order at the heart of confusion. A rational or aesthetic pattern underlying reality is far from a theistic God.

Asking about a time before the beginning of our spherical spacetime is like asking what lies north of the North Pole. There is no such thing.

Quantum mechanics is so counter-intuitive, physicists have never been able to come up with a comfortable picture of how it works.

Quantum events have a way of just happening, without any cause, as when a radioactive atom decays at a random time. Even the quantum vacuum is not an inert void, but is boiling with quantum fluctuations. In our macroscopic world, we are used to energy conservation, but in the quantum realm this holds only on average. Energy fluctuations out of nothing create short-lived particle-antiparticle pairs, which is why the vacuum is not emptiness but a sea of transient particles. An uncaused beginning, even out of nothing, for spacetime is no great leap of the imagination.

Attaching a Creator to the boundary is metaphysical skullduggery.