Key verse: Col.3:22a- “Slaves, obey in everything those who are your earthly masters.” (ESV)
One might argue that the context of 1st Century A.D.Roman slavery was significantly different than that of 21st century corporate America. I would suggest: If you are not able to set your own hours or your own pay scale and work at your own pace without outside pressure or coercion, then you are in in an economic condition of some servitude.
Certainly this is true for members of the U.S.Military. Although seasoned military personnel may have a measure of influence as to their location and schedule, they are still subordinate to the military structure and answerable to military authorities.
Even 'self-employed' persons have to please other persons with their work. If self-employed individuals consistently disappoint their clients/customers---or sneer at their demands--- they will find themselves unemployed eventually.
Centuries ago, the Baptist preacher John Gill spoke of the duty which Christians should render to their human masters: “Do it heartily, not by mere force and necessity, or grudgingly, with murmurings, but from the heart, and with good will, having a true and hearty affection for masters, having their good and interest at heart, and a delight [at being] in their service.”
The top priority for the Christian worker is to discharge God-ordained labor to the glory of God, to labor vocationally as a thank-offering to the Creator--- that is, to work as an expression of worship to the One Who has endowed us with the capacity to work in the first place. At the same time, though, we are to be dependable, productive laborers rather than defiant rebels to our human bosses. Christian workers are not to continually ignore and mock our supervisors and employers.
The principle is repeated in Eph.6:5-8— “ Slaves, be obedient to those who are your masters according to the flesh, with fear and trembling, in the sincerity of your heart, as to Christ; not by way of eyeservice, as men-pleasers, but as slaves of Christ, doing the will of God from the heart. With good will render service, as to the Lord, and not to men, knowing that whatever good thing each one does, this he will receive back from the Lord, whether slave or free.” (NAS)