From Wikipedia: "Called to Serve" is a hymn sung in The Church of Jesus Christ of Latter-day Saints (LDS Church). The words were written by Grace Gordon and the music by Adam Giebel. It is hymn number 249 in the 1985 LDS Church hymnaland is also song number 174 in the Primary's Children's Songbook. The words to the hymn reflect a desire to serve God and consequently the hymn is generally associated with missionaries and missionary work. The hymn has been translated into many languages and LDS missionaries called to foreign-speaking missions are often taught this song early in their language training. The phrase called to serve is associated with missionary work. Letters calling church members to full-time missionary service begin with the phrase "You are hereby called to serve...."
Lyrics: 1. Called to serve Him, heav'nly King of glory, Chosen e'er to witness for his name, Far and wide we tell the Father's story, Far and wide his love proclaim. (Chorus) Onward, ever onward, as we glory in his name; Onward, ever onward, as we glory in his name; Forward, pressing forward, as a triumph song we sing. God our strength will be; press forward ever, Called to serve our King. 2. Called to know the richness of his blessing-- Sons and daughters, children of a King-- Glad of heart, his holy name confessing, Praises unto him we bring. Text: Grace Gordon, alt. Music: Adam Geibel, 1855-1933