About the Title

A few resons for the title. First, a song called "Hear the Call of the Kingdom" by Keith & Kristyn Getty says this:
Hear the call of the kingdom;
lift your eyes to the King;
let His song rise within you as a fragrant offering
of how God rich in mercy
came in Christ to redeem
all who trust in His unfailing grace.

And secondly, Ephesians 5:2
And walk in love, as Christ loved us and gave himself up for us, a fragrant offering and sacrifice to God.