It is not unusual to hear discussions of the relationship between faith and reason, or science and religion, cast in terms of the blind acceptance of unquestionable propositions (religion) versus careful, skeptical, and critical rational reflection (science). Indeed, one of the hallmarks of religious faith, at least as commonly depicted in a great deal of our daily public discourse, is that it rests on claims that are “incontestable” – that is, impervious to skeptical scrutiny, empirical or logical analysis, or rational dispute. In contrast, scientific or secular knowledge claims are presumed to rest on “evidence” and the sure foundation of rational and/or empirical demonstration. As Suzanna Sherry (1996) has written, for example, someone operating under the epistemology of faith is “able to ignore contradictions, contrary evidence, and logical implications. Indeed, one test of faith is its capacity to resist the blandishments of rationality; the stronger the rational arguments against a belief, the more faith is needed to adhere to it” (p. 482). In contrast, “secular science and liberal politics, both committed to the primacy of reason, necessarily deny that any truth is incontestable” (p. 479).
Contrary to the naïve assumption that faith and reason must necessarily have a mutually allergic relationship, religious belief can often be strengthened and supported by critical, rational reflection. Indeed, as people of faith, we should always be willing to think critically about all of our beliefs. This does not mean we should approach intellectual questions about doctrines and beliefs with an attitude of scholarly aloofness or dismissive skepticism, nor does it mean that we should adopt a disparaging or fault-finding stance towards religious teachings. Good critical thinkers are not, as is sometimes uncritically assumed, relentless skeptics who – in Nietzsche’s (1967) memorable phrase – “worship the question mark itself as God” (p. 156). Being careful and reflective is not in any way incompatible with also being deeply optimistic and full of hope. Rather, thinking critically means that we look at our assumptions and contrast them with alternatives.
When we think critically, then, we question our basic assumptions in the light of competing or alternative assumptions. This does not necessarily mean we doubt or dismiss our assumptions — that is (again) the flawed fixation of the skeptic. Rather, it means we take them seriously by examining their origins and implications. For example, we might ask, “What does our belief system require of us that a contrasting belief system does not, and why?” Or, we might ask, “If this idea or belief is true, then where does it take me, both logically and practically, if I run with it all the way to its farthest implications?” Such questions are not full of skeptical and paralyzing doubt, but can rather reflect the attempt to more deeply understand (and live) our beliefs. It can also reflect a sincere desire to winnow out the chaff of sloppy thinking or incomplete understanding of our religious faith and spiritual commitments.
When we think critically in this way, we can better understand how our faith (and its assumptions about the world) differs from other perspectives and other beliefs, and what those differences might mean for us. Critical thinking can help us identify, and perhaps even reject, ideas that undermine the core assumptions of our faith. Conversely, it can help us be more open to ideas that do not contradict the core assumptions of our faith, but which at first glance may seem to do so. In short, by learning to think critically, coupled with the guiding influence of spiritual sensitivity, we can become more discerning and thoughtful religious believers. Remember, even Christ, the Son of God, amidst unimaginable suffering and agony upon the cross at Calvary, was willing to ask His Father a deep and troubling question:
And about the ninth hour Jesus cried with a loud voice, saying, Eli, Eli, lama sabachthani? that is to say, My God, my God, why hast thou forsaken me?” (Matt. 27:46)
Now, I assume it is possible that in that moment of utter extremity the Son of God, the Creator of the Universe, and the Savior of all mankind chose to abandon His faith and give in to the temptations of radical skepticism . . . but I doubt it.
 There is more than a little irony in Sherry’s claim that for the secularist committed to the primacy of reason no truth claim is incontestable, especially given that such a claim is itself an incontestable truth claim (see, Beckwith, 2015 for a more detailed discussion of this issue).
Beckwith, F. J. (2015). Taking rites seriously: Law, politics, and the reasonableness of faith. New York, NY: Cambridge University Press.
Nietzsche, F. (1967). The genealogy of morals (W. Kaufmann and R. J. Hollingdale, Trans.). New York, NY: Random House.
Sherry, S. (1996). Enlightening the religious clauses. Journal of Contemporary Legal Issues, 7(1), 473-495.