Since the early medieval period and the formation of what became the Holy Roman Empire, Christianity has been strong in the lands we now know as Germany. However, even with trade, politics, and other considerations shaping its history, religion in Germany is still an interesting subject. Today, let’s look at common religions in Germany.
Religion in the Constitution
The Basic Law solidifies the right to freedom of religion in modern Germany. This takes two aspects: both the negative freedom of religion (the right to not have to confess your faith, or any lack thereof, unless legally required to do so; also, the freedom not to be exposed to religion while in a state of subordination, for example) and positive freedom of religion. There is also no state church in Germany, though there is a thing called a church tax. More on this in the next section.
The two major Churches
Due to historical and cultural reasons, the largest religious organizations in modern Germany are the Protestant Evangelical Church in Germany and the Roman Catholic Church (both Christian movements). These churches are organized into legal corporations under public law, and enjoy certain benefits such as being able to provide religious education in state schools – for example, one denomination gives a lesson for members registered under their own denomination (Catholics would go to the Catholic-organized class, and so on). For smaller denominations or religious minorities, they may cooperate with these denominations or conduct classes outside school. Those who do not wish to participate in religious education at all must attend an alternative class called “ethics”. So the practice is a bit different from other countries, in this regard.
The Church Tax…
The church tax comes from a longstanding practice of a ruler maintaining churches, graveyards, and so on throughout history. Because of this, while Germany has no formal state religion, it devolved the church tax onto religious organizations – the tax goes towards upkeep of religious buildings, gravesites/cemeteries, salaries for clergy, and so on.
Only people registered under the denominations (which are registered as legal corporations under public law) have to pay church tax, with the idea that Catholics would then help to pay for the maintenance of their own (Catholic) churches, and so on. The Jewish faith is also considered a taxable faith, depending on the German state, due to the large population of Jewish people there (third-largest Jewish population in Europe). However, this also means that smaller denominations or those without a strong organizational system (such as Muslims) may not be included in this system of taxation and maintenance, as the system favors large well-structured religious organizations.

…and how to avoid it.
If someone does not wish to pay church tax, they can make an official declaration that they are “leaving the church” – in this case, leaving the religious organization. It may be that the number of people in Germany who do not self-identify as religious may be partly due to this church tax, as more people over time have filed to not be considered members. (You can see what it would cost, and how to file, at this website (German langua only). However, Catholic and Protestant clergy may refuse to bury someone who has formally left the faith, even if the person in question is still a believer. Currently, the issues revolving around church tax – who can administer it, who can distribute it, who has to pay it and why – are hot issues when it comes to matters of religion and the state in Germany. But as more people within Germany no longer identify with religious organizations, the religious organizations and churches in question are facing dilemmas about how to maintain themselves and how to change.
Islam and Juadism
Islam is notably the largest non-Christian religion in the country. Historically this was because of trade relations with the Ottoman Empire in the 18th century; nowadays, because of the postwar period and the inviting of foreign workers into Germany (notably from Turkey), German Muslims are not too uncommon, but find themselves in the midst of a tide of political debates in Germany, in Europe, and worldwide.
Many Jewish people also returned to Germany, notably after German unity, due to seeing German cities such as Berlin as more welcoming post-war than cities in ex-Soviet bloc countries.