As the main religion of Finland, but also of entire Scandinavia, Lutheranism has a centuries-long history. Until 1809 Finland formed the eastern part of the Swedish Kingdom, from 1809 to 1917 it was a Grand Duchy within the Russian Empire, and in 1917 Finland gained independence. In the 1520s the Lutheran Reformation reached the Swedish realm and gradually Lutheranism was made the state religion in Sweden. In the 19th century the Emperor in Russia recognized the official Lutheran confession and the status of the Lutheran Church as a state church in Finland. In the 20th century Lutheran church leaders preferred to use the concept people’s church. The Lutheran Church is still the majority church. In the beginning of 2015, some 74 percent of all Finns were members of the Evangelical Lutheran Church of Finland. In this issue of Perichoresis, Finnish historians interested in the role of church and Christian faith in society look at the religious history of Finland and Scandinavia. The articles are mainly organized in chronological order, starting from the early modern period and covering several centuries until the late 20th century and the building of the welfare state in Finland. This introductory article gives a brief overview of state-church relations in Finland and presents the overall theme of this issue focusing on Finnish Lutheranism. Our studies suggest that 16th and early 17th century Finland may not have been quite so devoutly Lutheran as is commonly claimed, and that late 20th century Finland may have been more Lutheran than is commonly realized.