Colossians 3:23: Studying Marketing for the Lord
Colossians 3:23 places the ordinary work of study under the Lordship of Christ: the audience is the Lord, not the classroom. Marketing can be studied wholeheartedly as service to Christ, without turning grades into a measure of your standing with God.
Avodah: work service and worship: A Biblical Guide
Joshua's covenant renewal at Shechem uses one word for work, service and worship, and it forces a choice between masters. Whole life allegiance to the Lord is the demand, not a religious compartment added to a neutral life.