What does secularisation indicate?

NCERT (2025-26): “6.3 Religion-related Issues and Identities … In the western context the main sense of these terms has to do with the separation of church and state. The separation of religious and political authority marked a major turning point in the social history of the west. This separation was related to the process of ‘secularisation’, or the progressive retreat of religion from public life, as it was converted from a mandatory obligation to a voluntary personal practice. Secularisation in turn was related to the arrival of modernity and the rise of science and rationality as alternatives to religious ways of understanding the world.”

“Modernisation and Secularisation … In the modern west, secularisation has usually meant a process of decline in the influence of religion. It has been an assumption of all theorists of modernisation that modern societies become increasingly secular. Indicators of secularisation have referred to levels of involvement with religious organisations, the social and material influence of religious organisations, and the degree to which people hold religious beliefs.…”