Peter Berger's The Homeless Mind thesis(taking his work as a whole)

For Peter Berger the sociologist , religion has always been a human construction, a social universe of meaning projecting a sacred cosmos. Because the supernatural is a realm set against the reality of every day life and is often seen to surround it, it can only be communicated by sacredness through religions' collective symbolisations. Sacredness is a quality of power realised in experience and objects of life. So religion is constructed to be a canopy of sacred objects and meanings, a universe of built meaning to reflect collective and therefore project itself right into the personal beliefs of the individual and human groups. Thus there is a relationship between institutions, the forms of work and life, and both social and inner meaning.
This sacred canopy is maintained by the social order, and in turn makes the objective social order subjectively legitimated to every thinking individual. The objective institutions of society are placed into history and the very drama of unfolding life, and that history reflects the playing out of divine reality. The Church, of course, is the key institution uniting the supernatural and the progress of the world.
Furthermore, the subjective impact of this construction and reflection is in the explanation of events of significance, thus explaining the perceived good and bad of life within that order. It pervades every area of life right down to the very personal, so that sexual relationships reflect the divine to human relationship, and health and wellbeing reflect the condition of the individual in relation to the divine will.
It is a very thorough, united and uniting ideological system with sacred and supernatural support, and through modernity it has been crumbling away into a shower of parts.
Modernity and pluralism have successively reduced religion to a private sphere. In the socio-economic sphere the change to bureaucractic, rational and technical modes of organisation and therefore ordinary practical-based thinking has undermined the social plausibility of the sacred. There has been a deinstitutionalisation of meaning (due to bureaucracy running on rational, technical grounds) and therefore religion.
Secularisation, that general area of consciousness once inhabited by the sacred canopy, is in a sense a by-product of choice, and secularisation also works at the level of the subjective consciousness. Secularisation is also the product of the Judaeo-Christian tradition itself, that Judaism and Christianity are this worldly and rooted in history and this location in this world (Christ was fully human) makes Christianity its own gravedigger (the Sacred Canopy, 1967, 129). Art, philosophy, literature and science move away from the domination of the agenda of the sacred. Secularisation is the way people ordinarily think day to day in contemporary times, as opposed to how they ordinarily thought in previous times.
A plurality of meanings replaces one general meaning and these often compete. This, in the Durkheimian sense, is seen as instability replacing stability, and thus Berger's use of the title "The Homeless Mind" (1974). This has deep social and pyschological consequences in terms of theodicy, in that what once could be explained in terms of life and death are now bereft of general explanation. We are seen to live in a meaningless state, and human life is less easy to bear. Secular ideological approaches have been nowhere near as successful in explaining a meaningfulness of personal events and place in the universe as the religions have been. Anxiety increases because anomie cannot any longer be resolved in a sacred order.
There is no general way back to rebuilding the sacred canopy. The ecumenical response after the growth of many denominations is an institutional rationalisation in the face of decline, but that is all they can do and they cannot rebuild that sacred canopy that once existed.
Another key response to modernity has been accommodations to it with changing theologies. They nip and tuck their dogmas and their understanding of dogmas to fit with modern plausibility, and yet it has been a losing battle of negotiation. Theology is therefore itself part of the sociology of knowledge - a change in ideas and understanding in response to social change. Some religious activists have reverted to traditionalisms of an alternative but removed counter-universe of meaning, while others as radicals absorbed the pluralist of the world and the secularisation of understanding. The least successful are the mid-way liberals with give and take. At the core of this shift is the loss of religion's plausibility structures - that institutions are no longer able to deliver meaning as they once did and so now we no longer believe in general these doctrines as given, the world view of causalities that they represent. It takes a huge sectarian effort to believe religious doctrines once taken for granted due to their loss of place.
Of course religious beliefs do not vanish. What is at stake is their de-legitimisation, the decline of general religious plausibility structures. However, within the generality of pluralism, and the competition of meanings, there is space for small resurgences of religion. Personal religion may be highly effective, but highly sectarian too.
In terms of sociology the Berger approach pursues a humanistic approach against an over emphasis on general structures and determinism, whilst taking structures into the approach. Like Weber, meaning at a subjective is given strong place in the context of bringing both macro and micro approaches together. Humankind has its place in society and the meaning of society is subjectively placed in humankind's consciousness. The references to culture, knowledge, meaning, and consciousness draw upon phenomenology and the very way we communicated and mean. Whilst changes in modernity can be discussed generally, Berger, the Lutheran, is interested in religion and its changes and responses to social change and sees religion contributing to social change through its history as well as being changed by broader forces.

Homelessness of the Mind

We want to link identities, consciousness and social relationships and this the Homeless Mind thesis tries to do. This approach encounters structuralism (a hint of Frankfurt School Marxism - a bit like the left idealism studied in criminology) and symbolic interactionism and phenomenology, and goes something like this...
Primary carriers of meaning are the institutions which form from the economic and social base of society. Market forces, privatised and anomic social relations, work identities separated from other identities, and the anonymity of bureaucracy. Secondary carriers are urbanism and the mass media, mass education, and areas of culture and arts transmitting ideas. This leads to existentialist doubt. This has echoes of the Frankfurt School of hegemonic Marxism and structuralism. But the self looks to society...
Berger and Kellner (1974) says we live in a framework of symbols and these convey meaning, and their pattern conveys overall meaning. In other words, the individual mind interacts with society on a sybolic interface.
In the past the main overarching symbol system was religious, giving one symbolic world, affecting consciousness, but now the overarching one symbolic world has been replaced by plurality of meanings. Because life has become segmented as in the life of the city, with bureaucracy and technology - we get anonymity and privacy and the allowing of a plurality of lifestyles. However, the city norms are not confined to cities - pluralism is everywhere. Thus a once sense of encountering the same home world in every situation of life has gone. We now have a segmented life carrying different meanings as we encounter each segment.
It is possible to imagine yourself having different biographies and offering a different identity of yourself to each segment. This gives freedom, but also frustration. It then becomes up to you to make and create your own meaning through your life plan. Who am I becomes what you do through space and time. It is uncertain and may not be achievable. In the old world of overarching meaning you were given your identity, but in the modern world you get a sense of designing yourself, but within the social situations in which you find and move yourself. So it is expnsive and free, but rootless and anomic. You migrate openly through different social worlds, and use their meanings.
Yet every meaning, because it is differentiated, is relativised. Nothing has absolute truth. This means the institutionl order as a whole no longer pins together as it did, and it itself is relativised. Because you cannot locate yourself in the whole objective order, as once possible, you sufer identity crises. But as you migrate you must reflect. It is not a given order, there is choice and reflection, requiring decisions and plans. So individualism is the key - what you choose is different from what they choose.
Religion which once produced an overarching view of reality - a cosmos - and was its principle project is now privatised. Because of this breaking down, there is a secularising effect. The generality is religionless - religion is now diffused. Religion has lost its quantity of certainty, faith is made more difficult, religion escapes increasingly from the public sphere and with the loss of metaphysics we all feel more homeless.