Europe has historically developed from state related monopoly churches controlling and regulating religion, to secular religiously neutral states with individual freedom of religion. In parallel Europe has continuously become more religiously and culturally diverse by globalisation, migration, travel etc. As part of increasing religious pluralism new questions on religion and possible needs for special regulation of religion are brought up in political and juridical context. Simultaneous with increasing use of the concept religion in secular legal context, it is questioned as a useful concept by researchers in religion. The concept religion it is too multifaceted and there is no common universal definition of religion. It is also criticised as being a western European social construction, which makes it especially problematic to use in general policies and common law in a religiously diverse society with many different understandings of “religion”. This chapter discuss the needs and limitations of regulation of religion, and question if secular states really need special regulation of religion. Is it not enough with the same common law for people of all kind of belongings, beliefs, values and practices regardless if they are religious, non-religious, political etc.? The European empirical context is in focus, although the theoretical discussion is largely general.