Ephesians 6:7

Good will. This may imply an even higher quality of service than “singleness of … heart.” The servant who takes a sincere interest in the welfare of his master and his business has already escaped the weight of his burden and is approaching the status of a freeman. Indeed, a slave, when he is called into the service of the Lord, “is the Lord’s freeman” (see on 1 Cor. 7:22). Principles such as these, embedded in the gospel of Christ, eventually destroyed slavery, and, in the meantime, gave relief to Christian slaves throughout the centuries. Granted good will, almost any barrier between men can be broken down.

To the Lord. The conviction that one is led by God is a most powerful incentive to the contented life, as is the knowledge that one’s efforts are accepted by God. The martyr faced the stake in this confidence, and the slave bore patiently his grievous wrongs because of it. However, the martyr’s courage and the slave’s patience do not make right the wrongs of the persecutor and the master. They must answer to God for their wrongs.