The hardest riddle

Question: I am god to many people despite not being a spirit. I am what people kill over, lust over, and fight over. I am not God or the Devil, but a mere material that people need endlessly. What am I?

Question: Look at my face, I am somebody. look at my back, i am nobody. What am I?

Question: What tastes better than it smells?

Question: What goes in the water black and comes out red?

Question: What asks but never answers?

Question: Resurrected, they descend by the millions. Sometimes, to nourish and give life. Other times, to take lives or destroy. They have been known to fill entire valleys and block roads only to disappear before executing their long journey back to the top. What are they?