Ladies and gentlemen, fasten your seat belts.
Germany is pretty democratic. It has general, direct, free, equal and secret ballots, separation of powers, a diverse press, political scandals, protests and demonstrations and political adherents which couldn't understand why the other adherents of the other party could vote them. So a boring normal democracy.
It is in fact so democratic that it ranks on the 13th place of the Democracy Index.
Let's imagine you have founded a certain religion. Once you are big and powerful enough...you may think: Hmmm, this whole business remembering the forgetful members to pay their membership fe...donations really irks me.
Then the church tax comes to your rescue. Currently the income is approximately 10 billion euros.
You must register your religion as corporate body, then you are able to receive the income the tax office has collected from your members. You could also collect directly from your members (Blame yourself, then). If you don't want to pay the tax...well, then you go to the state office, tell them you ain't a member anymore and the church tax ceases. The religion will then normally barring you from religious services, e.g. a Christian burial (if you are Christ) and other sacraments.
The highest German court came 2012 to the conclusion that this is legal. So you cannot say: I am a Catholic and I want to practice my religion, but I don't like the decisions of the higher members, so I don't pay tax. Nope.
Which leads us to an amazing topic: Religious education. Schools are offering what we call here Religionsunterricht. Girls and boys learn about the stories in the Bible in the first years and later discuss themes like death, drug problems, etc. etc. In Bavaria you are also reminded on their Christian background because the cross hangs on the wall. Uh, no, no, not only during the religious education...always. Isn't this unconstituitional ? Well, our highest German court said 1995: yes. And the Bavarians ignored the verdict completely, so business as usual.
And when you are not Christian ? Well, then you have alternative lessons. The lessons are graded, compulsory and accessed. So you can be left on the shelf if you get a 6 (the worst grade in Germany) in religious education. Until 10 the parents decide if you join religious education, after 12 you can veto the decision as child, after 14 you can left a religion by yourself.
How could we ? Well, simple, religion has no importance on German life. It is seen as own private choice, you could switch your religion anytime and if the education gives children a positive meaning of life, the better. And because the religious education aims to be tolerant, religious extremism is very rare (Yes, parents would strongly object that the part which stoning homosexuals should be teached to children).
When you have recovered enough, the next lesson of "What I never wanted to know about Germany" is: What a Personalausweis is, that you must have one and what a Einwohnermeldeamt does.