MICHELLE ASKS:

What is faith?

This is the simplest yet perhaps most difficult question in the brief history of “Religion Q and A.” Not the sort of thing journalists usually write about, but The Guy can at least report on what some thinkers have said about this.

Start with Merriam-Webster definitions:

(1) “strong belief or trust in someone or something.”

(2) “belief in the existence of God: strong religious feelings or beliefs.”

(3) “a system of religious beliefs.”

Number 3 is clear-cut but not what Michelle is asking (e.g. “the Catholic faith claims more than a million adherents”). Number 1 is often secular (“they have faith in the governor” or the New Yorker cartoon quip about stock market investments being “faith-based”). Number 2 is what this question is all about.

In Islam, the prominent scholar Habib Ali al-Jifri told a 2011 dialogue with Catholics, ”the technical meaning of faith is firm belief in something real, based on evidence. Experts in this subject have defined faith as being ‘to believe with the heart and proclaim with the tongue.’ ” He added that some like Abu Ubayd al-Qasim ibn Salam have added “to act on it with the body.”

The Jewish Bible (or Old Testament) puts deeds at the center, says the comprehensive Anchor Bible Dictionary: “Faith is described rather than defined.” The word usually translated as “faith” doesn’t link with “believe” so much as “sustain” or “support,” and the same Hebrew root gives rise to the word for firmness, as with a peg attached in a “sure” place in Isaiah 22:23. Modern Jewish theologian Martin Buber’s Two Types of Faith said Judaism emphasizes faith as firm fidelity toward God, while Christianity sees it more as belief or knowing about God. The latter emphasis is seen in a classic definition from Thomas Aquinas’s 13th Century Summa Theologica: “Faith is the act of the intellect when it assents to divine truth under the influence of the will, moved by God through grace.”

But Christianity involves non-intellectual aspects, too.

An oft-quoted New Testament depiction says “faith is the assurance of things hoped for, the conviction of things not seen” (Hebrews 11:1, Revised Standard Version). That’s followed by one of those sentences that can keep you up at night: “By faith we understand that the world was created by the word of God, so that what is seen was made out of things which do not appear.” (Big Bang theory, anyone?) But then this epistle defines faith not with theological abstractions but concrete examples of faith in God by the biblical Abel, Enoch, Noah, Abraham, Moses, and of all people, Rahab the prostitute.

Donald Hagner of Fuller Theological Seminary examines this in a Hebrews commentary using the Good News Bible, which renders verse 1 “to have faith is to be sure of the things we hope for, to be certain of the things we cannot see.” He thinks this can be understood subjectively, as the G.N.B. does, or objectively. The subjective means “assurance or inner certainty” of hopes, but the listing of ancient heroes isn’t about subjective confidence but actions. For Hagner, “to be sure of” or have assurance is subjective, but the objective sense is more natural, “expressing the basis or foundation” or hopes as in the King James Version’s use of “substance” or another translation’s “guarantee.”

The word translated as “be certain” could be subjective conviction but, again, Hagner prefers the objective understanding shown in the listing of heroes. “The action produced by faith is a manifestation or a proving of the reality of things not seen” in which “the unseen and the hoped-for become real. Faith expressed in this way can be said to objectify what is believed,” though the objective view presupposes subjective assurance.

Is Hebrews 11:1 saying faith is always mere hope without substance and things without evidence? Such is the attitude of the New Atheists, whose best-sellers were treated in a “Religion Q and A” posting on October 12, 2013. But analysts say Hebrews is talking about future and unseen matters, not the entirety of faith. Numerous thinkers blend religious faith’s subjective comforts with objective reasoning and evidences, for instance:

The book "Warranted Christian Belief" by Notre Dame philosopher Alvin Plantinga contends that religious beliefs are as sensible as numerous everyday convictions we necessarily live by.

This technical magnum opus is tough going for duffers like The Guy. Briefer and more accessible cases for faith as reasonable include "The Existence of God" and "Is There a God?" by Richard Swinburne, "The Justification of Religious Belief" by Basil Mitchell, and onetime atheist Alister McGrath’s books answering current atheism. All three authors are Oxford University professors. There’s also the hugely popular "Mere Christianity" by the late Oxbridge scholar C.S. Lewis, also a onetime atheist. A less intellectual yet intelligent discussion is "The Reason for God: Belief in an Age of Skepticism" by the Rev. Timothy Keller, New York City’s apostle to young skeptics.