Who is Emilio Sandoz from The Sparrow and what is their importance?

Emilio is the main character. He was born and raised in La Perla, Puerto Rico to an abusive father. The violence he met from his father made him learn to protect himself early in life. His surroundings lead him to a life of crime like his brother, father and grandfather, until his mentor, D.W. Yarbrough puts him on the path to becoming a priest. As a priest, Emilio masters every language he encounters and becomes a skilled linguist. When Emilio is introduced in the novel, he is fluent in Spanish, English, Greek, Latin, French, Italian and Portuguese. It is Emilio's skill as a linguist that leads him to the remainder of the characters in the book and the interplanetary mission.