Natural theology: What we can know about the being and nature of God through reason and evidence, apart from "special revelation" (e.g. prophets and scripture).

Evil: Bad things that happen. (Example: pain and suffering)

Moral evil: Bad things that happen because of what persons do. (Example: murder)

Natural evil: Bad things that happen for reasons other than what persons do. (Example: pain and death caused by hurricanes)

A Problem only for theists: The "Problem of Evil" is a problem only for people who believe in an all good, all knowing, God. If someone denies that God exists (or that God is good), she has no "problem of evil." A naturalist needs no special explanation of evil.