Do you know why lions roar?
If you research it, you'll find a variety of answers... but they're all connected to one big idea:
A lion roars because he has a strong sense of ownership over his domain.
So, for example, a lion might roar to warn other animals that they are encroaching on his territory.
It's because of this sense of dominion and responsibility over a certain space that the Christ figure, Aslan, in C.S. Lewis's classic work, The Lion, the Witch and the Wardrobe, was portrayed as a lion.
Through this allegory, Aslan represents Jesus Christ as the King of all creation... who sacrifices Himself to bring renewal to His domain... which is the whole world.
As those who are in Christ by faith, we partake in this renewal.
And though we may not roar like lions, we are to live with a fierce sense of ownership over the territory God entrusts to us... so we would do all we can to bring about good there.