Faith and Reason
The general consensus among the educated has long been that reason is at odds with faith in the same way that science is at odds with religion. The extent to which this is true depends on how faith and reason are each defined.
Some definitions of reason and faith indeed make them mutually exclusive. If reason is defined as belief only in what can be proven scientifically, then reason is clearly irreconcilable with faith. By the same token, if faith is defined as belief in that for which there is no evidence, then faith has nothing in common with reason.
To define reason as belief only in what can be scientifically proven, however, is to reduce reason to rationalism (more specifically, a form of rationalism called positivism). In everyday life, reasonable persons believe claims that cannot be scientifically proven. Which is to say that reasonable people have opinions. Reasonable people can, of course, support their opinions with evidence (which typically involves the interpretation of physical and/or historical facts in support of an opinion); this is what makes their opinions reasonable. However, if reason demanded belief in only what could be scientifically proven, then reason would exclude any beliefs other than scientific facts.
The difference between facts and opinions is not that the former are true while the latter are false. Rather, the difference between facts and opinions is that facts have been sufficiently verified by evidence so as to have become matters of consensus (meaning that virtually all agree) whereas opinions, as a general rule, cannot be verified, no matter how much evidence is presented to support them. Nevertheless, an opinion, while not verifiable, must be supported by evidence to be persuasive to reasonable people. While public discourse is frequently burdened by uninformed opinions, reasonable people distinguish themselves by forming and expressing informed opinions, that is, opinions that are informed and, as such, supported by evidence.
On the other side of the question, to describe faith as belief in that for which there is no evidence is to reduce faith to superstition. To the extent that it consists of superstition, of course, faith is at odds with reason.
The mystical character of so much of religious faith is largely responsible for the assumed opposition of faith and reason. Mysticism is belief that God is experienced intuitively, apart from the mediation of reason. Religious faith, so defined, presumes to be a kind of "spiritual" intuition, a sort of sixth sense—independent of either the five physical senses or the mind—through which one can gain access to and knowledge of the transcendent realm of the spirit, the invisible, eternal world beyond the visible, temporal world that is perceptible to the physical senses. The claimant to ESP (extrasensory perception, or the sixth sense) is believed to be especially attuned to the invisible world and, therefore, presumed to serve as a mediator, a catalyst who can awaken and cultivate the sixth-sensibility of those who are willing to believe.
In that no physical or historical evidence can be supplied for the existence of any such transcendent world, faith as the experience of this invisible, eternal world must exclude reason, because reason must demand some form of physical and/or historical evidence to support its conclusions. Naturally, then, the notion that faith and reason are unalterably opposed seems to follow.
Nevertheless, once the biblical definition of faith is distinguished from the common definition—as belief without regard to evidence—then the apparent dichotomy between faith and reason disappears.
Biblically speaking, faith is a matter not of intuition but of persuasion. Rather than a mystical activity, biblical faith is a rhetorical activity (rhetoric denoting the persuasive use of language). Which is to say that biblical faith consists of believing the words of a message, which the Bible calls the word of God. (Which is not to invalidate intuition as a form of knowledge, albeit uncertain; it is just to distinguish "spiritual" intuition from biblical faith in God.)
The biblical word of God was originally revealed by God to and through his prophetic messengers. Prophets were the biblical figures into whom God "breathed" the word through visions and dreams, calling them to speak the word to the public. (God’s "breath" is the biblical metaphor, appearing in the original languages of the Bible, from which evolved the English words "Spirit" and "inspired." Among the biblical prophets into and through whom God breathed the word are the NT Jesus and his apostles.) While it might be inferred that the visions and dreams of the prophets must have been in some sense mystical, or intuitive, biblical faith is never identified with the revelatory experiences of the prophets themselves. Instead, biblical faith is the experience of believing the word that the prophets spoke, which has been preserved for every generation to hear anew by the biblical writers.
Moreover, the biblical word of God takes the form of promise. From the beginning of its OT revelation in God’s promise to Abraham to the end of its NT revelation in the fulfillment of God’s Abrahamic promise through Jesus’ death and resurrection, the word emerges from the Bible as a story of promise and fulfillment.
God promises Abraham to give him a son, through whom God promises to make of Abraham a great nation, through which God promises to bless all nations (see Gen. 12:1-3; 15:1-6; 18:18). After the revelation of the promise in Genesis, the Bible tells the story of its progressive fulfillment. The promise of the son is fulfilled in Isaac; the promise of the great nation is fulfilled in Israel (and its "promised land"); and the promise of the international blessing is fulfilled in Jesus, whose death replaces the national ("old") covenant between God and Israel with an international ("new") covenant between God and both Jews and Gentiles, and whose resurrection gives the international community of faith the hope of resurrection from death to everlasting life in the kingdom of God (coming, according to the biblical message, to renew and transform life on earth).
The persuasive content of biblical faith as promise and fulfillment distinguishes it from all intuitive forms of religious faith. Which is to say that nothing in the biblical message—also called "the word of faith" (Rom. 10:8)—is self-evident to any form of "spiritual" intuition. And because faith in the biblical message depends on persuasion rather than intuition, the tension between faith (at least of the biblical variety) and reason disappears.
How so? Insofar as the biblical testimony about the progressive fulfillment of God’s Abrahamic promise—especially in the forms of the birth of Isaac and the exodus of Israel and, chiefly, the resurrection of Jesus—serves as evidence to support the claims of the biblical message.
In regard to Jesus’ resurrection, hearers of the biblical message are not called to wait for a "religious experience," in which they "see" Jesus in a vision or "hear" his voice in a dream or otherwise feel themselves overpowered by his spiritual presence. The testimony of post-apostolic Christian mystics and charismatics notwithstanding, to anticipate such an experience is to confuse God’s revelations to the biblical messengers themselves—those into and through whom God breathed the word—with the experience of believing their message and so, being filled with God’s breath. To believe the biblical message is to experience the persuasive power of the biblical testimony about Jesus’ death and resurrection as the means of entrance into the coming kingdom of God (the persuasive power of the message being, biblically speaking, the power of "the Spirit").
Hearers of the biblical message of Jesus and the kingdom of God are not called to believe without evidence. Instead, they are directed, first, to the evidence of the progressive fulfillment of God’s Abrahamic promise in the OT history of Israel, which led to the coming of Israel’s Anointed One (Hebrew, Messiah; Greek, Christos), Jesus, to proclaim the kingdom of God, to be crucified for sins, and to be resurrected from the dead. And, second, hearers of the biblical message are directed to the evidence of the eyewitness testimony of Jesus’ apostles about his resurrection. From a band of disappointed and frightened former disciples of their crucified master (and, in the case of Paul, a former persecutor of Christians), they were transformed by their witness of the risen Jesus into proclaimers of the message of Jesus and the kingdom of God (called "gospel," that is, good news) to all nations.
The Bible tells the story of the progressive fulfillment of God’s Abrahamic promise and, therefore, the story of the progressive revelation of the message about how the promise reached its fulfillment in Jesus. And how that fulfillment offers hope of resurrection to everlasting life in the coming kingdom of God to all nations. (Biblically speaking, then, the word of God is not the Bible itself but the biblical message: the gospel of Jesus and the kingdom of God; the Bible itself is not the message but the messenger, the inspired story-teller.) As such, the Bible appeals to human reason, calling the hearers of its message to a faith predicated on understanding.
In fact, the biblical meaning of "hear" is not merely to physically perceive the sound of the message but to mentally perceive its meaning; that is, to "hear" the message is to understand it, just as to believe the message is to be persuaded by a biblical understanding of it. As Jesus said, "He who has ears to hear, let him hear" (Mark 4:9; see also Matt. 13:23 for the importance Jesus placed on understanding).
The biblical emphasis on faith as understanding and persuasion throws all claims not only to mystical experiences but also to mystical doctrines into doubt as to their biblical authority. Ecclesiastical doctrines such as the Trinity and the immortality of the soul are—unlike clear biblical claims about the exodus of Israel and the resurrection of Jesus—unsupportable by any physical or historical evidence.
The doctrines of the Trinity and the immortality of the soul are also demonstrably post-apostolic, originating in the neo-Platonization of the Christian tradition by the Church councils of the third and fourth centuries, a fact that any volume of Church history will attest. Significantly, Christians can believe all that is explicitly identified by the NT writers as the apostolic gospel of Jesus and the kingdom of God without even paying lip service to mythical belief in a "God-in-three-Persons" or an immortal soul (both of which are, at best, inferred from selected NT texts).
In short, biblical faith cannot exist in the human heart apart from the exercise of reason. As God says through one of the prophets, "Come now, let us reason together" (Isa. 1:18).