The concept “religion” is multifaceted. It is used in different ways in different social, cultural and academic contexts, often without definition. This is unproblematic as long as religion is part of theoretical discussion, kept within the private sphere. But the concept “religion” becomes a highly problematic issue when it is used without definition in public debate, political discourse or applied in cases of conflict. This becomes especially significant concerning references to the principle of “Freedom of religion”. Since this principle is highly valued in many legal systems, it is of need to critically scrutinize the concept “religion”. The aim of this paper is to contribute to this critical discussion.

Individuals' religion can be described and defined in terms of belonging, believing or practicing, and by combinations of these three dimensions. In sociological statistics it is common to define religion in terms of belonging or believing, but often without motivating why one or the other of these dimensions is used. Belonging and believing are mostly unproblematic as long as these dimensions don't affect the public sphere. Conflicts' concerning the recognition of religion with reference to “Freedom of religion” has in most cases to do with the third dimension, practice. The use of this dimension as religious expression is however increasingly problematic because of the increasing divergence between practice, belonging and believing among people belonging to a specific religious tradition. Along with society's increasing pluralisation and individualisation, the differences of religious practice within groups of the same religious belonging increase continuously. What has previously been regarded as religious practices thereby becomes increasingly visible as historic cultural practices, not directly linked to the belonging or beliefs of a certain religious tradition or group. This highlights the questions: How should we define the concept religion? What practices should be regarded as religious?