"The only thing we can and should trust is the sciences"

That's one of my claims in chapter 4 of The Christian Delusion (p. 89). I had previously argued that Christians use the naturalistic scientific method when they debunk the religious faiths they reject (p. 86), and later on in that same chapter I argued that without a better alternative method this is all we have (p. 94). I mean, really, is there any comparison to accepting blindly what we learned on our mama's knees, or through an "inner witness of the Holy Spirit," or the poor evidence of historical evidence, or a the warming of the bosom? Come on. Let's get real.

But a Christian can still say:
Unfortunately, this claim isn't a deliverance of any natural science. Science can't tell us something like this.
Sure it can and does. As Barbara Forrest argues:
The relationship between methodological and philosophical naturalism, while not one of logical entailment, is the only reasonable metaphysical conclusion given (1) the demonstrated success of methodological naturalism, combined with (2) the massive amount of knowledge gained by it, (3) the lack of a method or epistemology for knowing the supernatural, and (4) the subsequent lack of evidence for the supernatural. The above factors together provide solid grounding for philosophical naturalism, while supernaturalism remains little more than a logical possibility. Link.
What do you want, a massive probability with science or a mere possibility?