From a wise friend on Facebook:

You are right to say that persecution should not take place for the reason that we share an essential humanity.

But what should happen and what does happen are often quite different. Christians are possibly more widely persecuted for their faith around the world at present than any other single group, and that is largely because Christianity is seen as representing a threat.

Perhaps you need to look more closely into what different religions actually believe: it will help you understand the roots of persecution. Islam, in particular, emphasises conformity through submission. In many countries it is interpreted to authorise the punishment including execution of those who leave it because they no longer submit and are therefore a threat to society.

Although Christianity after Constantine had a similar approach, it never rejected the prophetic impulse which declares that “The Lord hath yet more light and truth to break forth from his holy word.” It is therefore intrinsically more open to dissent than Islam is, though the more closely it allies itself with the State, the less open it becomes.

There is a good case that the concept of pluralism, which our world often thinks its own invention as a consequence of The Enlightenment, is actually an invention of Christianity. (Thomas Helwys, pastor of the first Baptist Church in England, wrote an appeal for total religious toleration some 70 years before Locke took up the idea, and continental Anabaptists made more limited appeals for religious toleration nearly a century earlier.)

Without a concept of toleration of difference and dissent, a brother or sister who deviates from the received truth is still a danger to the family, to be brought back, made to comply or, if all else fails, destroyed.”