CONTRARY TO WHAT MIGHT SEEM OBVIOUS, DOUBT ISN’T THE ENEMY OF FAITH. Certainty is. In fact, doubt and faith, properly understood, are complementary drivers in a dialectic of growth. Certainty, on the other hand, stalls growth and often weakens faith.
The primary problem behind our common misunderstanding of doubt and faith is our tendency to take “faith” to mean “belief.” Saying “I believe in God,” for example, doesn’t mean the same as saying “I have faith in God,” even though both statements affirm the existence of God. The statement of belief says one accepts as factually true the proposition “God exists.” It’s a direct acknowledgement of God’s existence. The assertion of faith, on the other hand, is an indirect reference to God’s existence, and it takes a step beyond belief to include trust. In other words, “I have faith in God” implies an acceptance of the existence of God, but declares “I trust God.” So, one could believe God exists without trusting God, but one can’t trust God without believing in God.
Our confused understanding of belief and faith well may trace back to the early years of Christian thinking. In the original Greek texts of the Christian Testament, the word translated into English as either “faith” or “belief” is simply pistis, and as a verb, the obviously cognate pisteuo. The connotation of the Greek, however, leans toward “faith,” even though there is no other word in Greek for “belief.” Latin, on the other hand, has separate words to convey these two concepts: credo (I believe; without a cognate noun) and fides (faith, trust, confidence; with the verb form confideo, literally “with faith”).
When Christianity became an accepted religion in the Roman Empire under Constantine, the emperor assembled a council of bishops at Nicaea in 325 CE, and insisted they agree on a clear statement of beliefs. The result was the Nicene Creed. In the Creed, statements that were rather vague and ambiguous in Greek (pisteuo, I believe in or I have faith in or I trust) became clear and unambiguous in Latin (credo, not confideo). In the 17th century, the Creed was translated into English and “I believe” came into play (a word derived from Old English).
If we try to steer clear of the confusion, and understand faith as trust, a constructive role for doubt as a complement to faith comes into sight. The key to understanding the dialectic between the two lies in realizing that we can trust without understanding. We can, we must, we have no choice but to trust God without fully understanding God.
Doubt, then, questions the adequacy of our understanding. Living doubt’s questions pushes us to expand our understanding, to study and learn more, to experience and know more — always trusting God is, and is with us. Grounded in faith, doubt leads us on a path of ongoing spiritual growth that, with God’s grace, may end in mystical union, in gnosis, an experiential knowing that transcends belief.
Do you see, now, how certainty can be the enemy of faith? Certainty is unquestioning belief. It allows no room for doubt. It provides no possibilities for growth. Where faith and doubt soften us into a humble openness that encourages growth and loving acceptance, certainty of belief hardens us into an arrogant rigidity that all too easily leads to stagnation, intolerance and hatred — even to oppression and violence.
Ironically, if you look deeply under such hardness of heart, you’ll find a weakness of faith and a lack of trust. To paraphrase the final exhortation Moses delivered to the Israelites (Dt. 30:19): One path leads to life and growth, the other to stagnation and death. Choose life.

