The activity that would be forbidden in Nazi Germany would be publishing a newspaper editorial that criticizes the country's leaders.
Christianity & Shintoism is not major factor in southeast Asia....
My opinion:
I would say my neighbors share some of the same cultures, Christmas, Thanksgiving, Halloween (whatever you believe is a tradition). I certainly know we don’t share the same religion. Some believe in God and etc. some don’t. It’s better for everyone to share either the same or different culture. It is possible to share the same one.
Answer: The Earth's crust that formed these mountains was once covered with an ocean