Good and evil are both part of our experience. It is experienced as suffering. Evil, then, in the most comprehensive sense is the disruption or destruction of a potential for enjoyment in sentient beings, especially animals and humans. Hence, evil is not primordial but emergent and occurs when a possibility for good is frustrated or destroyed. Given the nature of finitude and the complexity of organization that enjoyment in organisms requires, evil can and will most probably occur.
Sentient beings are vulnerable to destruction because of internal failure and external conflict.
I do not find the notion of truth as correspondence to reality useful when dealing with ultimate matters. Rival doctrines confront and eliminate each other in endless rounds of debate. I am a pragmatist. Theories are worthy of belief by particular persons if they are useful to them in accounting for known relevant evidence in the most compelling fashion and in providing a way of coping with life's problems and challenges. Theories can be tested in life in terms of whether in the light of all considerations they produce coherent doctrines that harmoniously integrate available evidence in the most productive way and lead to satisfying consequences.