As far as I know, the overall population of Christianity is growing, but the growth pattern of the religion is not the same in all parts of the world, and that is why Islam is regarded as the fastest-growing religion in the world. In Africa, Christianity is growing very rapidly, especially when you consider its growth pattern over the last century.
Most African governments are not being hostile to this religion, and most Africans now think of religion as the most peaceful religion compared to others. The religion is also growing and getting more followers in the Middle East and in Asia.
The problem of terrorism has forced so many people to align their faith with Christianity. However, Christianity is currently facing problems as followers of the religion are renouncing their alignment with the religion in North America and Europe. For instance, there are reports that show how Christianity is facing a sharp decline in the United States.