Crockett estimates that in 1851, 40% or more of the adult population of Britain attended church on Sundays, which led some to claim that the 19th century was a 'golden age' of religiosity.

Wilson argues that western societies have been undergoing a long-term process of secularisation, where ' religious beliefs, Practices and institutions lose social significance'.

Only about 6% of the adult population attended church on Sundays in 2005, halving since the 1960's and likely to fall further. Sunday school attendance, Church weddings and baptisms are declining.

Overall, religious affiliation is declining. Since 1983, adults with no religion have risen from a third to a half, and those identifying as Christian have fallen by a third.

Some small organisations have grown. The number of Catholics has increased slightly, due to East-European immigration. Non-Christian religions have also increased, due to immigration and higher birth rates.

Evidence from 80 years of surveys shows a decline in belief in God, in Jesus as the son of God and in Christian teachings about the afterlife and the Bible.

Bruce agrees with Wilson that all the evidence on secularisation has shown that 'there is a study and unremitting decline'.

The influence of religion as a social institution is declining. Religion once affected every aspect of life, but now is relegated to the private sphere of individual and family.

The state has taken over many of the functions the church used to perform, e.g. schooling.

The number of clergy fell from 45000 in 1900 to 34000 in 2000, while the population increased in size, reducing the church's local, day-to-day influence. Bruce predicts the Methodist church will fold by 2030 and the CoE will merely be a small voluntary organisation.

Although there is an increasing number of 'faith schools' in the UK - implying continued religious involvement in education - they are mainly state-funded and must conform to the state's regulations.

Religion may have declined in Britain but not necessarily in America or elsewhere, so secularisation may not be universal.

Secularisation and the decline of religion have often been linked to major social changes such as modernisation, industrialisation and its effects, and increased social and religious diversity. Sociologists have developed several explanations of secularisation.

This is the process by which rational ways of thinking and acting replace religious ones. Max Weber argues that Western society has undergone this in the last few centuries.

The 16th century protestant reformation undermined the religious worldview of the Middle Ages, replacing it with a modern rational scientific outlook.

The medieval Catholic worldview saw the world as an 'enchanted garden' in which God, angels etc. Changed the course of events through their supernatural powers and miracle-working interventions.

The protestant reformation brought a new worldview that saw God as existing above and outside the world, not as intervening in it. The world had become disenchanted, left to run according to the laws of nature

Events were thus no longer to be explained as the work of unpredictable supernatural beings, but as the predictable workings of natural forces.

This enables science to develop, giving humans more power to control nature, further undermining the religious worldview.

Through reason and Science, humans could discover the laws of nature, and understand and predict how the world works. Religious explanations of the world are no longer needed.

Bruce argues this has largely replaced religious explanations of why things happen. Religious worldviews only survive in areas where technology is least effective, e.g. praying for help if you are suffering from an incurable illness.

Parsons defines structural differentiation as a process that occurs with industrialisation as many specialised institutions develop to carry out the different functions previously performed by a single institution, such as the church.

Religion dominated pre-industrial society, but with industrialisation it has become a smaller and more specialised institution.

Bruce agrees that religion has become separated from wider society and privatised in the home an family. Religious beliefs are now largely a matter of personal choice, While traditional rituals and symbols have lost meaning.

Even where religion is involved in education or welfare education or welfare, it must conform to secular controls; e.g. teachers in faith schools must hold qualifications recognised by the state.

Church and state are usually separate in modern society, so the church loses political power.

Wilson argues that in pre-industrial society, local communities shared religious rituals that expressed their shared values, but industrialisation destroys these stable local communities and so destroys religion's base.

Bruce sees industrialisation creating large, impersonal, loose-knit urban centres with diverse beliefs, values and lifestyles. This diversity undermines the believe-ability of religion.

The rise of individualism leads to a decline in community-based religious belief and practice.

Aldridge points out that a community does not have to be in a particular locality. Religion can be a shared source of identity on a worldwide scale, e.g. Jewish communities. Also, Pentecostal and other groups often flourish in supposedly 'impersonal' urban areas.

Berger argues that another cause of secularisation is the trend towards religious diversity.

In the middle Ages, the Catholic Church held an absolute monopoly and had no challengers. Since the 16th century Protestant Reformation, the number and variety of religious organisations has grown, each with a different version of the truth.

Berger argues that this religious diversity undermines religion's 'plausibility structure' - its believability. Alternative versions of religion enable people to question all of them and this erodes the absolute certainties of traditional religion.

Bruce sees the trend towards religious diversity as the most important cause of secularisation, because it is difficult to live in a world containing a large number of incompatible beliefs without concluding that none of them is wholly true.

Cultural defence: Religion provides a focus for the defence of national or ethnic group identity in a struggle against external force, e.g. Catholicism in Poland before the fall of Communism.

Cultural transition: Religion Provides a sense of community for ethnic groups living in a different country and culture.

Bruce argues that cultural defence/transition don't contradict secularisation theory, since religion only survives in these situations as a focus for group identity and not as an expression of religious faith; e.g. once communism had fallen in Poland, church attendance fell.

In 1962, Wilson found that 45% of Americans attended church on Sundays, but this was more an expression of the 'American way of life' than of religious beliefs. For Wilson, America is a secular society, because religion the has become superficial.

Opinion Polls asking people about church attendance suggest it has been stable at about 40% of the population since 1940. However, this figure may well be an exaggeration.

Hadaway et al found that in one county in Ohio, the attendance level claimed in opinion polls was 83% higher than researchers actually counted going into church. Evidence suggests this tendency to exaggerate churchgoing is a recent development.

Bruce argues that in America, the emphasis on traditional Christian beliefs and glorifying God has declined. Instead, religion has become 'psychologised' - a form of therapy

American religion has remained popular by becoming less religious - it has become secularised from within. Its purpose has changed from seeking salvation in heaven to seeking personal improvement in this world.

Bruce identifies practical relativism among American Christians - i.e. accepting that others are entitled to hold beliefs different to one's own.

Lynd and Lynd found in 1924 that 94% of churchgoing young people agreed with the statement 'Christianity is the one true religion'. By 1977 only 41% agreed.

Absolutism has been eroded -we now live in a society where many people hold views that are completely different to ours, Undermining our assumption that our own views are absolutely true.