Why were all people, sinners? The Bible says, “For all have sinned, and come short of the glory of God” (Romans 3:23). Humans are imperfect, so they commit wrongdoing and sin that are incompatible with God.
God saw people were corrupted in Genesis 6. So, what precisely is the status of being corrupted? God views corruption through sins. Also, the status of being corrupted led to spiritual death as Adam and Evan sinned.
Why God made good and evil trees? I was struck when I read the book of Genesis. I found the idea that the good and evil tree reminds God is the creator of Adam and Eve. It seems like a safeguard against falling, as Satan did.