He was a high ranking Roman Army Officer. He's important because he, with all his great power and ability to command, was very humble and very faithful in Christ's power. Perhaps I'm using the wrong word, but don't forget the centurion recognized power before anything. He is remarkable because he did not respond exclusively to power. He responded to his understanding of faith.
Read Matthew 8:5:13. It's in Luke to but I'm not familiar with it in that gospel.
Id say that its “to persuade your reader that you have a reasonable position”
She is so beautiful, loving, kind, her hair shimmers like stars in the moonlight, her eyes are like tiny suns, her laugh is like a bubbling stream, her figure is more beautiful than Aphrodite. She is his Goddess, his savior, his light. He devotes all his time to making her feel happy.