Why is this the answer?

The answer is candle because this clever poem-riddle is telling the life story of how a candle lives and works. It uses beautiful but tricky words to describe something you use to make light when it is dark. Let's look at the words like clues in a secret treasure hunt to find out why this is the right answer. The first line says, "Always wax, yet always wane." You know that a candle is made of wax, which is the solid, colorful part of it. To "wane" is a special way of saying that something gets smaller. Think about when you have a brand new, tall candle. Every time you light it, the wax melts and disappears little by little. So, the candle is always getting smaller or "waning" as it gives you light. The next part, "I melt, succumbed to the flame," is a very clear clue. What is the only thing that melts right next to the fire? It's the wax. The big word "succumbed" just means the wax has to give in or surrender to the fire's great heat. When the fire gets too hot, it melts the solid wax and turns it into a little liquid puddle that feeds the flame. The third clue is, "Lighting darkness, with fate unblest." This describes a candle's main, important job. A candle's purpose is to light up a dark room so you can see. It has a special "fate" or destiny. But the word "unblest" means its fate is not happy, because to give all that light, the candle must burn up and disappear. It sacrifices its own life to help you see in the dark. Finally, the riddle says, "I soon devolve to shapeless mess." If a candle burns for a long time, the tall, straight wax starts to drip down the sides. It loses its nice, perfect shape and becomes a messy pool of liquid wax at the bottom of the holder. This is exactly what happens to a candle when its whole life is over. All these clues about being made of wax, melting from a flame, making light in the dark, and becoming a messy puddle perfectly describe a candle. It is a wonderful riddle that makes us think about this everyday object in a new and exciting way.