Multiple Possible Causes

If an omni-benevolent God exists, then there are several possible explanations why birth defects exist. Assume for the sake of this discussion that an all-powerful and all-knowing God exists and is the original creator of everything originally created. By that assumption, God created the physical world including the genetic make-up of human beings. On these assumptions it is possible that some birth defects are caused by actions of humans and are a human responsibility. If humans through their actions pollute their environment with toxic materials that cause birth defects, then the moral responsibility lies with those humans. Other situations are entirely different. God is the creator of the zika virus and the creator of the mosquito that carries it, and so the deity bears the ultimate responsibility for the birth defects caused by that virus. This is the sort of natural evil that causes some thinkers to question God’s existence.