“The standard model of physics presents a theory of the electromagnetic, weak, and strong forces, and a classification of all known elementary particles. The standard model specifies numerous physical laws, but that's not all it does. According to the standard model there are roughly two dozen dimensionless constants that characterize fundamental physical quantities...

Physicists have determined the (approximate) values of the fundamental constants by measurement. (There's no way to derive the values of the fundamental constants from other aspects of the standard model. Any quantities that could be so derived wouldn't be fundamental.) Still, the underlying theory favored some sorts of parameter-values over others. ... Physicists made the startling discovery that –– given antecedently plausible assumptions about the nature of the physical world –– the probability that a universe with general laws like ours would be habitable was staggeringly low.

We thus focus on a package of three propositions: (i) the proposition that given the general laws, only a minute fraction of values of the cosmological constant (as judged by any of the physically-respectable measures) are life-permitting; (ii) the proposition that quasi-theism is false; and (iii) the proposition that physical reality consists of a single universe. We will call this “the package.” Our core argument is that if one supposes the package to be true, then theism is significantly more plausible than atheism. We are not claiming that we know that the package is true; we're just trying to figure out what its ... significance would be. 

We should emphasize just how small we take the life- permitting parameter values to be according to the physically-respectable measures. “Small” here doesn’t mean “1 in 10,000” or “1 in 1,000,000”. It means the kind of fraction that one would resort to exponents to describe, as in “1 in 10 to the 120”. The kind of package that we have in mind tells us that only a fantastically small range is life permitting. 

So ... how does atheism fare conditional on the package plus [the fact that life exists]? It is quite easy to make the case that it fares badly. The central thought is that the package plus life is fantastically unlikely conditional on atheism but not nearly as unlikely conditional on theism. Let's suppose that theism was not anything like fantastically unlikely to begin with (as seems reasonable to us). The result will be that, conditional on the package plus life, theism will be substantially more probable than atheism."