An adherent of the Religion of Peace describes the punishment for apostasy:
The key difference between ISIS and Muslims in the West is that ISIS can enforce Islamic laws in the lands under their control. Muslims in the West are too few in numbers for now. That's why the open borders of Europe, Canada, and the US are a long term disaster. It allows Muslims to build up their armies and then inflict their evil ways. They are not interested in assimilation or peace. Theirs is a centuries-old cult of domination and war.