The biggest question in apologetics: If God exists and is truly good and all powerful, then why is there so much evil, pain and suffering in the world? Why?
The answer requires a theodicy (a vindication of God in light of the existence of evil). I cannot answer that question. Nor, can I adequately explain the origin of evil. I will, however, give you my understanding of the fundamental issues. Hopefully, in them, you'll find something helpful in defending your faith in God and the precision and accuracy of the Word of God, the Holy Scriptures that carry the Gospel out to all mankind that they may be saved. And in doing so, that no matter the circumstance, you'll remain standing as an anvil well beaten. God is good. In a word evil is Godlessness, the absence of God.