The separation of Church and state in the American system involves obvious problems, but on the whole it has worked out well both for religion and for secular society. To have a lively religious community it is important that the members belong by free choice and for religious motives, not because of any kind of social constraint or legal penalties. Churches thrive better in the United States than in countries where some form of Christianity is the official religion of the state. Provided that its free exercise is safeguarded, religion can survive and prosper in a secularized state. But the kind of religion that will prosper depends to a large degree on the impact of cultural secularization.
Cultural secularization goes hand in hand with what sociologists describe as modernization.
This becomes clearer by contrasting traditional cultures and those that are characteristically modern. In traditional societies the religion, occupation and customs of individuals are determined not by personal choice but by the family and neighborhood in which they were born and raised. Modern society, by contrast, is highly mobile. People change their residence and occupation very freely. This individual choice often carries over into the sphere of religion.