I therefore, the PRISONER of the LORD, beseech you that ye walk worthy of the vocation wherewith ye are called. Ephesians 4:1.
Paul was at this time apparently writing from the confines of the Roman Correcional facility in Rome.
Whether he was confined in a lockup prison or in a relaxed facility may be open to debate. But he may have had his Prison Identification Number (PIN) apparently inscribed on his clothes or something to identify him to all as a prisoner.
Paul, however, chose not to identify himself as a prisoner of Rome.
Rather, he chose to identify himself as a PRISONER OF THE LORD JESUS!
The import of that was that he saw himself bound more by the orders of the Lord than those of the Roman authorities.
He was a prisoner to and of Jesus to the extent that his actions and inaction were bound by what Jesus instructed.
As a prisoner is limited and bound by the orders of the Warder, so Paul was bound by Jesus!
It was upon this that he instructed in 1 Corinthians 7:23 thus “Ye are bought with a price; be not ye the servants of men.”
Given that we were bought with the blood of the Lord, let us focus our attention on Him who bought us in all our dealings.
Beloved, may God guide and guard you in your service to our Lord as His prisoner.