I have some questions for the posters here.

[Deesse23]

Like if you believe in God in Germany you have to give 10% of your paycheck to Church.

Wrong. Twice

#1
You have to pay as long as you are a member of the catholic or protestant church. Actual belief is not checked.

#2
Its not 10%, its 10% of your income tax, which depends on your income (progressive income tax), but is in the 20% ballpark. That makes church tax 10% of 20% of your income: 2%

Addendum:
Its easy to leave church. Takes about 10mins in the townhall, no questions asked, no pressure applied whatsoever