The purpose of this book is not to decide the religious issue of the present day, but merely to present the issue as sharply and clearly as possible, in order that the reader may be aided in deciding it for himself….

In the sphere of religion, in particular, the present time is a time of conflict; the great redemptive religion which has always been known as Christianity is battling against a totally diverse type of religious belief, which is only the more destructive of the Christian faith because it makes use of traditional Christian terminology. This modern non-redemptive religion is called “modernism” or “liberalism.” Both names are unsatisfactory; the latter, in particular, is question-begging. The movement designated as “liberalism” is regarded as “liberal” only by its friends; to its opponents it seems to involve a narrow ignoring of many relevant facts. And indeed the movement is so various in its manifestations that one may almost despair of finding any common name which will apply to all its forms. But manifold as are the forms in which the movement appears, the root of the movement is one; the many varieties of modern liberal religion are rooted in naturalism — that is, in the denial of any entrance of the creative power of God (as distinguished from the ordinary course of nature) in connection with the origin of Christianity….

The rise of this modern naturalistic liberalism has not come by chance, but has been occasioned by important changes which have recently taken place in the conditions of life. The past one hundred years have witnessed the beginning of a new era in human history, which may conceivably be regretted, but certainly cannot be ignored, by the most obstinate conservatism…. Modern inventions and the industrialism that has been built upon them have given us in many respects a new world to live in; we can no more remove ourselves from that world than we can escape from the atmosphere that we breathe.

But such changes in the material conditions of life do not stand alone; they have been produced by mighty changes in the human mind, as in their turn they themselves give rise to further spiritual changes. The industrial world of today has been produced not by blind forces of nature but by the conscious activity of the human spirit; it has been produced by the achievements of science. The outstanding feature of recent history is an enormous widening of human knowledge, which has gone hand in hand with such perfecting of the instrument of investigation that scarcely any limits can be assigned to future progress in the material realm.

The application of modern scientific methods is almost as broad as the universe in which we live…. No department of knowledge can maintain its isolation from the modern lust of scientific conquest; treaties of inviolability, though hallowed by all the sanctions of age-long tradition, are being flung ruthlessly to the winds.

In such an age, it is obvious that every inheritance from the past must be subject to searching criticism; and as a matter of fact some convictions of the human race have crumbled to pieces in the test. Indeed, dependence of any institution upon the past is now sometimes even regarded as furnishing a presumption, not in favor of it, but against it….

If such an attitude be justifiable, then no institution is faced by a stronger hostile presumption than the institution of the Christian religion, for no institution has based itself more squarely upon the authority of a by-gone age…. Christianity during many centuries has consistently appealed for the truth of its claims, not merely and not even primarily to current experience, but to certain ancient books the most recent of which was written some nineteen hundred years ago. It is no wonder that that appeal is being criticized today; for the writers of the books in question were no doubt men of their own age, whose outlook upon the material world, judged by modern standards, must have been of the crudest and most elementary kind. Inevitably the question arises whether the opinions of such men can ever be normative for men of the present day; in other words, whether first-century religion can ever stand in company with twentieth-century science….

From every point of view, therefore, the problem in question is the most serious concern of the Church. What is the relation between Christianity and modern culture; may Christianity be maintained in a scientific age?

It is this problem which modern liberalism attempts to solve. Admitting that scientific objections may arise against the particularities of the Christian religion — against the Christian doctrines of the person of Christ, and of redemption through His death and resurrection — the liberal theologian seeks to rescue certain of the general principles of religion, of which these particularities are thought to be mere temporary symbols, and these general principles he regards as constituting “the essence of Christianity.” …

[O]ur principal concern just now is to show that the liberal attempt at reconciling Christianity with modern science has really relinquished everything distinctive of Christianity, so that what remains is in essentials only that same indefinite type of religious aspiration which was in the world before Christianity came upon the scene. In trying to remove from Christianity everything that could possibly be objected to in the name of science, in trying to bribe off the enemy by those concessions which the enemy most desires, the apologist has really abandoned what he started out to defend. Here as in many other departments of life it appears that the things that are sometimes thought to be hardest to defend are also the things that are most worth defending….

In view of the lamentable defects of modern life, a type of religion certainly should not be commended simply because it is modern or condemned simply because it is old. On the contrary, the condition of mankind is such that one may well ask what it is that made the men of past generations so great and the men of the present generation so small. In the midst of all the material achievements of modern life, one may well ask the question whether in gaining the whole world we have not lost our own soul. Are we forever condemned to live the sordid life of utilitarianism? Or is there some lost secret which if rediscovered will restore to mankind something of the glories of the past?

Such a secret the writer of this little book would discover in the Christian religion. But the Christian religion which is meant is certainly not the religion of the modern liberal Church, but a message of divine grace, almost forgotten now, as it was in the middle ages, but destined to burst forth once more in God’s good time, in a new Reformation, and bring light and freedom to mankind. What that message is can be made clear, as is the case with all definition, only by way of exclusion, by way of contrast. In setting forth the current liberalism, now almost dominant in the Church, over against Christianity, we are animated, therefore, by no merely negative or polemic purpose; on the contrary, by showing what Christianity is not we hope to be able to show what Christianity is, in order that men may be led to turn from the weak and beggarly elements and have recourse again to the grace of God.

J. Gresham Machen, excerpt from Christianity and Liberalism (Grand Rapids, MI: Wm. B. Eerdmans, 1923), 1–7. Used by permission of William B. Eerdmans Publishing Co.