The Church becomes for all practical purposes a voluntary association. Religion is considered a private matter in which people can make their own choices. Many opt out of the church and the religion in which they were raised. Sometimes they come back to it, sometimes they join another religious body. Modern societies also tend to divide life into separate spheres.
Religion is seen as having a certain limited competence.
It governs people s relationship to God, their prayer life and their weekly worship. But most believers do not want religion to interfere with the autonomy of their other activities. In this situation religion tends to get marginalized, some would say trivialized. It has a very hard time maintaining itself in the public square or the marketplace. Any effort by a Church to say what is morally permitted, required or prohibited by the law of God in the spheres of politics, medicine, business or family life is resented as an intrusion.