This has been the case for nearly 2000 years.
Are you being serious? Because centuries of Christian dominance in Europe would tell you otherwise.
Roman persecution, other European pagans, Islamic invasions, religious violence in the Reformation, the rise of Communism. Had Hitler been successful he had plans to eventually eliminate Christianity as well.
And then, of course, there is the rest of the world.
No pagans have killed as many Christians for religious reasons as Christians did. As I said, killing Christians seems to be the main Christian doctrine: at least, it is the one thing they all happily do.
When have emergent Christians killed anyone?