The individualization thesis advanced by sociologists of religion such as Grace Davie, Danièle Hervieu-Léger, Michael Krüggeler, Thomas Luckmann, Hubert Knoblauch, Wade Clark Roof, Wayne E. Baker, and others has become increasingly widespread especially in Europe within the sociology of religion. In contrast to the secularization theory it assumes that processes of modernization will not lead to a decline in the social significance of religion, but rather to a change in its social forms. According to the individualization theory, traditional and institutionalized forms of religiosity will be increasingly replaced by more subjective ones detached form church, individually chosen, and syncretistic in character. The article examines the empirical applicability of the individualization thesis on the basis of how religiosity and church affiliation have evolved in Germany over the past 50 years. It comes to the conclusion that the rise of individually determined non-church religiosity cannot compensate for the losses of institutionalized religiosity, since non-church religiosity remains rather marginal and is interwoven with traditional Christian religiosity. Religious individualization is only a component of the predominant secularization process.