The navel represents the body's consciousness, the root cause of the 10 central vices. The 10 main vices are lust, anger, greed, attachment, ego, jealousy, hatred, deceit, stubbornness and laziness, which are represented by the 10 heads of Ravan. It is shown in the Ramayan scripture that when Shri Ram tried to bring down any of the 10 heads of Ravan, they came back. Ravan got killed only when Shri Ram aimed at Ravan's navel. Only when we become soul-conscious and remember God or the Supreme Soul and finish our body consciousness by doing that do all our vices get destroyed.
Shri Ram is symbolic of God, and Ravan is symbolic of evil that rules over every soul's personality in the world today. When we imbibe God's goodness in our personality, we burn the 10-headed Ravan in our nature. Burning the effigy of Ravan every year is a symbolic representation of this process, which takes place when God performs the task of world transformation and establishes Ram Rajya or Heaven in the world by destroying Ravan or evil from and purifying all the souls of the world.
Every year, the height of Ravan's effigy is increased compared to when it was burnt in the previous year. This is symbolic of the vices in the world, which are growing every year, and impurity and negativity in their different forms are taking control of human beings more and more with time.
When God performs the task of world transformation at the end of every World Cycle, i.e. at the end of Kaliyug or the Iron Age, every soul who is the child and also the beloved of God is represented by Shri Sita in the Ramayan is in sorrow and under the negative influence of Ravan, imprisoned by him.
Gyanshree School, Noida