Final answer:
The song is called 'Jesus, My God, I Know His Name' by John A. Lomax. It is a gospel song that reflects religious beliefs and emphasizes the endless possibilities of the world.
Step-by-step explanation:
The song that starts out a cappella and has the lyric 'you don't know what you're missing, the world is at your command' is called 'Jesus, My God, I Know His Name' by John A. Lomax. The song is a gospel song that reflects the religious beliefs of the artist. The lyric emphasizes the idea that the world holds endless possibilities for those who believe and embrace faith.