How did the German public school system get to maintain religion as a standard subject in all grades in the face of the church-state separation?

by llevar

I know that from a historical perspective it is usually more difficult to answer questions about why something didn't happen in a satisfactory manner. Nevertheless, I'm hoping to learn about potentially crucial events and people that have allowed Germany, which is largely seen as a progressive and modern nation, to retain such an archaic practice well into the 21st century.

For those who are not aware, in the German public school system, through all grades children are taught Catholic or Evangelical Christiantiy as a substantial part of their standard curriculum. For instance, in Grade 1, religion constitutes about 10% of the overall teaching time, about the same as physical education. Parents are able to opt the children out of the religion classes, but very frequently nothing is offered instead. The kids are put in a room and are told to read or do their homework.

I find this situation very strange, and would like to figure out why religion perseveres in this state in the education system.

Thanks in advance.

Sn_rk

For those who are not aware, in the German public school system, through all grades children are taught Catholic or Evangelical Christiantiy as a substantial part of their standard curriculum. For instance, in Grade 1, religion constitutes about 10% of the overall teaching time, about the same as physical education. Parents are able to opt the children out of the religion classes, but very frequently nothing is offered instead. The kids are put in a room and are told to read or do their homework.

This isn't true. Every religion or confession of a religion has the right to offer religious education. Multiple Länder offer Jewish and Muslim religious education programmes, Berlin also offers Buddhist religious education, while almost all offer either secular ethics/philosophy lessons (one or two exclusively, even) or general religious education instead of being confessionally bound.

The only exceptions are NRW and Bremen as the former doesn't offer secular alternatives prior to 5th grade while the latter only offers the choice between Christian religious lessons and, rarely, secular ethics lessons. (here's a list of all the different programmes, courtesy of REMID).

In short, what you consider to be an "archaic practice" is just the acceptance of any religion as an important part of people's lives and the acknowledgement that it's best to teach people about it in a way that prevents extremism (all teachers have to study at university and be examined in their subjects and the lessons have to be in accordance to German law and custom).