In many places surveyed, 20% or more of all adults have left their childhood religious group. Christianity and Buddhism have had especially large losses. Pew Research Center.
Religion is not necessarily the same as religious institutions. Christianity is quite an outlier with its heavy centralization in the case of Catholicism, but there is many denominations of Christianity that are not adhering to a centralized institution.
Religion is not necessarily the same as religious institutions. Christianity is quite an outlier with its heavy centralization in the case of Catholicism, but there is many denominations of Christianity that are not adhering to a centralized institution.