Is there such a thing as replenishing the earth? When the bibble says mankind is here to replenish the earth we might assume that the earth had been plenished before. Just sayin'.

Having come from Mormonism, ex-Mormon or former Mormon are rather commonly used terms for some time. By extension, I would have assumed ex-Christian would also have been in common use. I would think the term would have useful descriptive application and would not necessarily be an equivalent to atheist. Someone could leave Christianity to become a Muslim or some other theistic religion. They would still be ex-Christian, but not atheist. Add the term to our vernacular? Certainly! It is descriptive.