I agree, of course, with everything you said in your post. But push your idea further and ask not why idealist exists, for it has always been around, but why is it winning now?
The only explanation I found for myself is that religion became defensive as science and industrial revolution started to roll. You don't have to be a historian and look back two centuries: consider "the pill." The only answer to the increasing ease of sexual intercourse without biological consequences is an increase in moral responsibility. I do not think either Jewish or Christian leaders offered a real answer to the pill when it appeared in 1960s. There answer, "Don't use it," was and is suitable for VERY observant people, and these are the ones that need help least. Leadership was required, explaining to people that, just as technology makes killing easier, it does not become more morally justified, contraceptives do not decrease moral aspects of sexual relations, which are given to use to give life. That is just one example.
Every time "the church" and "the synagogue" took a step back, it created vacuum. It is into this vacuum that the idealism you referred to stepped in. This utopian ideal took different forms but was always the same at the foundation: it replaced G-d in heaven with man-god. And, as Dostoyevsky pointed out, man-god is not bound by anything; man-god can march through the Earth and cover it in blood. It did --- in Nazi Germany, Soviet Russia, communist China... This march of idealism continues --- and only because we allow it to happen by not offering a strong MORAL alternative in the language understandable by most. We preach to the converted, the choir that is getting smaller and smaller...
The moral alternative to humanism is divine law. Humanists reject the concept outright.
You may argue quite fairly that the church has been a poor demonstration of the transformative power of the gospel, but let's not pretend that secular humanism does not consider revelation an execrable superstition, and that stance closes the secular ear to any moral alternative.
The response of the world to the message of God's love is: war. Unilateral war. They are not innocent of His blood, nor do they lack His emissary.
Your post:
Every time "the church" and "the synagogue" took a step back, it created vacuum. It is into this vacuum that the idealism you referred to stepped in. This utopian ideal took different forms but was always the same at the foundation: it replaced G-d in heaven with man-god.
Reminded me of the following "diagnosis" of the problem from Jacob Needleman in his book "The New Religions." The context for this quote is an essay on why Eastern Religions were becoming so popular in this country during the 60's & 70's:
Various rituals, prayers, services and the like no longer function as part of the mechanics of the religious process, but mainly as an emotional 'lift', something to help us return to our ordinary life feeling better, psychologically more secure. In this way they help to preserve the quality of the life we lead, rather than transform it.This general forgetting of the instrumental nature of religious forms is in a way really quite bizarre. It is as though millions of people suffering from a painful disease were to gather together to hear someone read a textbook of medical treatment in which the means necessary to cure their disease were carefully spelled out. It is as through they were all to take great comfort in that book and in what they heard, going through their lives knowing that their disease could be cured, quoting passages to their friends, preaching the wonders of this great book, and returning to their congregation from time to time to hear more of the inspiring diagnosis and treatment read to them. Meanwhile, of course, the disease worsens and they eventually die of it, simling in grateful hope as on their deathbed someone reads to them yet another passage from the text. Perhaps for some, a troubling thought crosses their minds as their eyes close for the last time: 'Haven't I forgotten something? Something important? Haven't I forgotten actually to undergo treatment?'
It is impossible to say when this forgetting of the fundamentally instrumental nature of the religious forms began in the West. But obviously the general clergy--priests, ministers, and rabbis--forgot it quite as much as their congregations. No wonder the young became disillusioned with religion. They heard exhortations, commandments, prescriptions by the basketful, but nobody was telling them how to be able to follow them. I do not say they formulated it this way to themselves, but they--and not only they--saw the absurd discrepancy between the ideal preached in their churches and the actual behavior of men, behaviour which seemed reinforced rather than seriously challenged by religion.
The Eastern teachings which are attracting so much interest in this country have by and large preserved this instrumental aspect of their religion. That is why they come to us with such things as meditation techniques, physical and psychological excercises, and why they tend to emphasize the necessity of a guru or master. It takes no great research to discover that practical psychological methods were always a central part of Christianity and Judaism, and that they still exist in monastic settings, or, for example, amoung certain communities such as as the Jewish Hasidim. The point is that this aspect of religion has been forgotten by almost all other Westerners.
It was only because it was forgotten that Judaism and Christianity were so shaken by psychoanalysis and various other movements in modern psychology. Compared, for example, to the early Christian diagnosis of the inner human condition, Freud's 'expose' of the nature of human motivation is a very weak tea indeed. For one thing--and this is the very least of it--he retained his trust in the power of reason, his own, and observation, also his own, to arrive at the truth about human psychology. But for the early Christians, and for several of the most interesting new teachings, the power of thinking and observing clearly is a quality of a higher state of consciousness, and not something that man is able to rely on without work in a spiritual discipline.
The main point here, however, is that because of the instrumental nature of religous forms was forgotten, the science of psychology suddenly appeared as something new. Such an absurdity could only arise on the basis of a total misunderstanding or ignorance of the history of Judaeo-Christian thought and practice. One need only glance again at the writings of Augustine, Eckhardt, the Eastern Orthodox Fathers, or the great rabbis to confirm this point.
-- Jacob Needleman, The New Religions. New York: Crossroad, 1987 (1970), 17-18