To whatever extent men reject God they must attempt to replace Him with something in their own experience. In rejecting God men suppose that He is, in fact, easily removed by man's intellectual dismissal. Whenever man dismisses God from his thinking, however, a vacuum is left which must be filled.
As men seek to fill that emptiness, they find it necessary to "play God." To reject God inevitably leads to the elevation of another in His place. In modern thought the replacement for God is manifested as the authority conferred on man and the resulting folly of humanism. The humanist, in fact, can best be described as one who "plays God," or as Satan said in Eden, presumes to "be as gods" (Gen. 3:5).
The Question of Authority
If God is real, then obviously the man in rebellion against accountability to Him has a problem-he's fighting a losing battle against reality; he's trying to "kick against the pricks" just like Saul (Acts 26:14). The consistent humanist has an impossible void to fill. Man without God seeks to know and understand in terms of himself what is, in fact, beyond him.
Biblical faith is in God, not man. Biblical man sees himself in terms of God and His revelation. There are two great limitations on men according to Scripture. First, creaturehood defines man's position and responsibility in relation to the Creator. A creature can never presume the prerogatives of his Creator. Even in Eden, sinlessness was still in the context of creaturehood. Man was under the authority of God and his life and its terms were at His discretion. A second limitation on man is the fall. Man's very creaturehood has been corrupted by his own actions. Accepting the reality of sin is prerequisite to true conversion, which involves repentance of sin and faith. The Christian must not only accept these limitations, he must understand himself as well as his relationship to God in terms of both creaturehood and the fall.
Non-Christian thought rejects both. Naturalism rejects man's creaturehood and effectively makes mankind the supreme being, the highest pinnacle of the evolutionary process. The roles are then reversed, because God is then at best an unnecessary concept created by man. He is, moreover, rudely dismissed as an illegitimate supernatural intrusion into naturalism's narrowly-defined reality. Without God there is no creaturehood and no higher power to hold men accountable for sin. Freud thus described guilt as man's latent memories of the semi-human acts of the struggle for survival.
The doctrine of the sovereignty of God is essential to more than just man's salvation; it governs all of life and action. The premise that a Sovereign God not only decrees and determines but reveals Himself infallibly is central to Christian thought: it establishes a reliable authority, a source for truth on which man can depend. A limited or subordinate deity is an oxymoron.
Ancient man had no such certainty, and did not want it. The first heretical movement to challenge Christianity after the apostles was Gnosticism, a mingling of many religious traditions which acknowledged a supreme being as a very remote first cause but specifically defined him as unknown and unknowable even to himself. All knowledge of higher things, the Gnostics said, was indirect, known via many levels of truths from the supreme being. These emanations were known only to the select few. Faith in the Gnostic sense was faith in these men who were attuned to such secret knowledge. The theological battles of the early centuries of the church were largely battles against such ideas infiltrating the church as higher understandings of the faith.
Rationalism is the reliance on reason as man's primary means to knowledge and truth. Rationalism overtly or effectively ignores both creaturehood and the fall and therefore puts an impossible burden on man's mind. Reason, if defined as thought or logic, is a valid tool, but rationalism gives it a position of preeminence.
Rationalism emerged in the Enlightenment as a self-conscious move away from dependence on faith and revelation. This was a reaction to the theistic thought of medieval Christendom and, more immediately, to that of the Protestant Reformation. The Enlightenment was a revolution in Western thought and is still largely the framework of the modern world. The shift was toward a new authority, that of man's reason over revelation. Higher criticism of Scripture is thus a rationalistic religious trend that sees man as the highest authority and God's Word as subject to man's final word. The same could be said of religious modernism in general.
The Enlightenment's emphasis on reason represented more than a shift in thinking; it meant a change in the very concept of reality. If religion addresses ultimate concerns, the change since the Enlightenment has been a religious shift of monumental proportions, so much so that we might consider Darwin's later naturalism as a necessary corollary to rationalism. Evolution removed the necessity of God as a "first cause"; it completed the restructuring of reality and thought into a godless world and life view. Man was no longer merely preeminent; he was alone in a pantheon of his own construction.
Many will hyperventilate if you speak against reason. They will assume you might also deny gravity or advocate a flat earth. For many people reason is "all we have" because they assume reason is man's most reliable intellectual tool. They do so because they think along rationalistic lines.
The Limits of Reason
Reason is limited by man and his experience. Aside from his creaturehood and sin, man is limited by his finitude. Man cannot experience all the potentialities of his world and there are certain realms he cannot experience at all. Rationalism ascribes to man's reason unlimited responsibility with limited ability. If reality is at all what Scripture says it to be, however, reason is a valid but limited tool.
Rationalism limits understanding by effectively denying there is a mind greater than man's. This is why Intelligent Design is rejected by the rationalist. One would think design implied a designer, but such an implication is too theistic for the modern naturalist. Intelligent Design is rejected out of hand because it implies a higher designer, effectively a deity. Intelligent Design is not creationism and will not end in the God of Scripture, so its limitations are real. It is, however, an interesting point of logic that questions the very reasonableness of naturalism's exclusion of God.
Man cannot understand everything he experiences. All the collective minds of men of all time could not understand all reality, yet rationalism demands that we limit our thinking to the parameters of human experience and exclude as illegitimate the revelation of God in Scripture.
Rationalism in the Church
One's view of the place of reason is based on one's view of man. If man is seen in subordination to God, reason will be seen as subject to faith in Him and His revelation of truth and knowledge. If reason is not so limited by faith and revelation it will be seen as superior to both. Any approach which places such an undue reliance on reason will rewrite both its theology and its anthropology to give man preeminence.
Sadly, rationalism has had quite an influence in the church. For some, reason has been equated with the image of God in man, so that man becomes closer to his Creator by his intellectual pursuits. This, of course, goes hand in hand with an effective denial of the full effects of the fall, for the mind of man then becomes not a manifestation of sinfulness but a glimpse of his divine potential.
Rationalism has not been limited to the liberal church, though. Many conservative thinkers so believe in the modern reliance on reason, they begin their theological discussions with the supposition that all doctrines must be understandable to man because reason is a kind of common bond between the mind of God and that of man. The result is a convoluted and ostensibly erudite language by which they discuss what they do not and cannot truly understand. The faith of such men is in reason as much as in God and His Word. Their presupposition about the dependability of human reason makes it and not faith their fall-back position.
The Irrationality of Rationalism
We cannot put full reliance on our reason or we make more of ourselves than Scriptures says we are. We would then become the authority; we would then be playing God with a swelled head. It was, after all, the rationalizations of the serpent that Eve relied upon when he made God sound unreasonable. The answer to such intolerable behavior by God was for Adam and Eve to defy His law-word. The question in the garden quickly came down to one of authority-God or Satan, and Satan's logic made sense in Eve's mind. Her sin, then, began when she intellectually ascribed greater authority to the serpent and her own discernment than to God. Is our reason now more reliable than Eve's?
When man elevates his reason, conflicts will result. He therefore has to define certain areas of thought as illegitimate. Modern science is now wholly dependent on rationalism, just as medieval thought was self-consciously (if imperfectly) theological. Truth is now seen as a scientific fact, not a theological one. God has thus been excluded from science, and the supernatural is seen as illegitimate in a naturalistic worldview. The logic of rationalism ends up excluding God from a discussion of His own Creation.
When a rationalist does address faith and religion, he does so as mere aspects of man's experience. Faith is then an aspect of man's psychology, of man's pursuit of a felt need. Religion represents man's primitive means of searching for truth. It is viewed as a crutch for an area man does not yet understand but might yet one day. The rationalist sees faith and religion as side rails where many stop while others pursue truth more scientifically. To them, faith is a blind belief in nothing by those who have abandoned reason. The question rather is one of authority, man or God.
To the Christian, faith is a God-given confidence in the truth of His revelation. True knowledge then starts with faith: "Through faith we understand ..." Hebrews 11:3 instructs us. Faith is not in nothingness. It opens our sin-plagued understanding to the higher authority of God and His Word. It is rationalism that restricts thought to man and his narrow realm of experience.
When Reason Became Unreasonable
The modern cult of reason began with the Enlightenment's self-conscious revival of ancient humanism as an alternative to the Reformation's theistic thought. The ability to reason is now said to be what makes man different from other organisms, not the image of God. (This is why scientists are still unduly fascinated by any observation of sequential thought processes in animals.) The reasonableness of placing so much importance on man's mind was never itself established, however, because it was assumed as part of Enlightenment thought. This rationalistic supposition is essentially no different than what the Christian calls faith. Rationalism is faith in man and his reasoning, whereas Christianity is faith in God and His revelation.
The Enlightenment's confidence in reason was predicated on an intellectual and moral climate still heavily dictated by centuries of Christendom. What was "reasonable" was in fact the influence of Christian morality and thought. People were in the habit of acting in those long-established patterns, just as many people in the 1950s and ‘60s acted along more traditional lines even when they had no personal Christian faith.
Even "God" was borrowed by the Enlightenment thinkers. He was retained as a first cause, even though His "revelation" was transferred to a new vehicle that came to be called "Nature." God was still the originator of all things even if it was now interpreted in terms of the laws of Nature.
Eventually, however, a spoiler came along in the person of Charles Darwin. Darwin's naturalism claimed that man's reason came very late in the evolutionary development. If Darwin's chronology is accepted, giving any credence to reason is illogical. If anything was ultimate and determinative in Darwin's science it was chaos, randomness, and violence by the physically strong, certainly not reason.
Darwin's thinking, when assumed to be correct, really makes rationalism's dependence on reason itself unreasonable and illogical in terms of the newly accepted evolutionary timeline. Modern thought since Darwin has often, in fact, followed this backward progression into meaninglessness, chaos, and revolution. The assumption of progress borrowed from Christianity has now broken down as man's reason tells him all is meaningless nothingness. Darwin's naturalism removed any Biblical view of God from the realm of modern thought. In removing Him from the hierarchy of authority it left only man and his reason. Darwin thus elevated man, yet the implications of his thought also made man irrelevant and his life void of any possibility of relevance. Any meaning presumed by naturalism today represents a borrowing from Christianity, unconvincing makeup on Darwin's pig.
Rationalism is still given lip service by modern man, but it has been largely abandoned by modern thought. It represents an obviously borrowed desire for meaning and progress. Modern thought is now largely void of any real conception of truth or knowledge. This is evidence of its decline and coming death. In a time of crisis it will offer no hope or solace to man, only the echo of his descent into meaninglessness. The alternative, a rigorously Biblically-based faith and thought, will then appear far more reasonable to humbled men.