"Freedom of faith and of conscience, and freedom to profess a religious or philosophical creed, shall be inviolable."
This article maintains that practising all religions are allowed in Germany, and everyone is free to have any belief. All can pray as they wish- and nobody is allowed to disturb.
People are also free not to have a religion at all: Just like religions, different worldviews are allowed- Everyone can believe in what he or she wants. Article 4 also says that the state cannot force anyone to fight (in a war).