Something that is necessary is 'needed'.
Answer:
Sin
Explanation:
In Dante's Inferno (part of The divine Comedy), the author is narrating his spiritual experience when he gets lost, away from the right path, in a dark forest. Being a Christian, he wants to reach for the sun's light, symbol of the good, but he is hindered by these animals: a leopard, a lion, and a wolf that represent sin (<em>lack of self-restraint, violence, and deception</em>. )
