He goes on to mention that atheism was his own belief during much of his earlier academic life:
I became an atheist early in life and long believed that my fellow nonbelievers were an enlightened bunch. I relished citing studies appearing to show that atheists have higher IQs than believers. But when I was studying for my doctorate in physics, math and astronomy, I began questioning my secular worldview.In the course of this exploration he learned three things about worldviews:
First, ... all worldviews are built on core beliefs that cannot be proved. Axioms from which everything else about a person’s perception of reality is derived. They must be accepted on faith.As has been pointed out in this space on other occasions, the naturalist must assume that our reason evolved to make us more fit to survive, it didn't evolve for the purpose of finding truth. Thus, both the theist and the atheist must accept by faith that reason is a reliable guide to truth.
Even reason itself—the vaunted foundation of atheism—depends on faith. Every logical argument begins with premises that are assumed to be true. Euclid’s geometry, the epitome of logical reasoning, is based on no fewer than 33 axiomatic, unprovable articles of faith.
The theist accepts that because the theist believes that reason is a gift from the Creator who is Himself reasonable. The naturalist believes reason is the result of a mindless process that by sheer chance produced the rational faculty that by a fortuitous coincidence sometimes helps us find the truth.
Second, ... every worldview—that is, every person’s bubble of reality—has a certain diameter. That of atheism is relatively small, because it encompasses only physical reality. It has no room for other realities. Even humanity’s unique spirituality and creativity—all our emotions, including love—are reduced to mere chemistry.For the naturalist, god is the cosmos, humanity, the state, or oneself. It is what they consider to be of ultimate importance and to which they pledge, consciously or unconsciously, their fealty and devotion.
Third, ... without exception, every worldview is ruled over by a god or gods. It’s the who or what that occupies its center stage. Everything in a person’s life revolves around this.
What naturalists fail to grasp is that almost everything we believe, we believe to a greater or lesser extent by faith. Very little that we believe in life can be proven to be true. We can only accumulate more and more evidence in the belief's favor.
Of course, people, whether religious or secular, often believe things on the basis of little or no evidence. To believe something despite the lack of evidence is "blind faith," but true faith is believing (and perhaps trusting) despite the lack of proof.
Atheists like biologist Richard Dawkins are fond of saying that theisms like Christianity require "blind faith" whereas naturalism is based upon empirical evidence, but neither clause in that claim is true.
There's a substantial body of evidence for the main themes of theistic belief, so, if one insists on evidence to justify belief in God, there's plenty there to warrant it.
On the other hand, naturalists believe, and must believe, a host of things for which there's no evidence at all.
They believe, for instance, that life originated through purely unguided, mechanistic processes; that the universe came into being from non-being; that there are an infinity of other universes besides our own; that moral and aesthetic judgments are actually meaningful assertions despite lacking any objective ground for them; that there are no immaterial substances such as minds; that their reason is a reliable guide to truth; that the laws of physics apply consistently throughout the universe; and much else.
There's no evidence for any of these beliefs and lots of evidence, in some cases, against them. They're all instances of "blind faith."
Guillen adds this:
When I was an atheist, a scientific monk sleeping three hours a day and spending the rest of my time immersed in studying the universe, my worldview rested on the core axiom that seeing is believing. When I learned that 95% of the cosmos is invisible, consisting of “dark matter” and “dark energy,” names for things we don’t understand, that core assumption became untenable.Here's a short video featuring an interview with the very prominent agnostic astronomer, the late Robert Jastrow, who discusses his own struggle to maintain his agnosticism in the face of the theistic implications of the empirical evidence that scientists were discovering:
As a scientist, I had to believe in a universe I mostly could not see. My core axiom became “believing is seeing.” Because what we hold to be true dictates how we understand everything—ourselves, others and our mostly invisible universe, including its origin. Faith precedes knowledge, not the other way around.