With respect, none of my stories get promoted by Medium either, but I've got a solid readership. I think you misunderstand something. Christians aren't being persecuted.

To be persecuted means to be locked up and the keys thrown away, to be tortured, to die in a gas oven, etc. Having people mock you is not being persecuted. It just doesn't feel good, if that is not what one wants.

Medium does not promote stories that are anti-Christian. What is happening is that the vast majority of educated people no longer buy into myths, and Christianity is very much regarded as a myth.

So the algorithm, which is automated, promotes the stories which are most read. Christian stories are not read by secular people, and there are a lot more of them than you think.