but, it isn't contrary to christian teachings, or at least not contrary to the calvinist ones.

the fact is that it was often used by protestants to try and kill off catholics and control the descendants of the slaves and indigenous groups. and, let us remember that slavery itself comes to us via religion, as well, even if many prohibitionists were, in the end, driven by religious conviction.

https://creation.com/images/pdfs/tj/j20_3/j20_3_54-60.pdf