This verse is parallel to Colossians 3.22. When they are watching you translates the Greek phrase “in eyeservice” (the noun is found only here and in Col 3.22), meaning service performed while being watched by the master, contrasted with genuine service well performed, whether or not the master is watching.

You want to gain their approval translates the Greek compound word “men-pleasers” (Revised Standard Version). It may mean human approval in general, but here it probably has the masters in view, again in contrast with service that is performed in order to please the divine Master. Because you want to gain their approval may be expressed as “because you want them to think that you have done well” or “to say that you have done well.”

With all your heart translates “from the soul” (as in Col 3.23). In some languages an expression such as “doing what God wants with all your heart” may seem very strange, since the “heart” is not related to work or activity. The emphasis is really upon one’s whole being and may be equivalent to “put all you have into doing what God wants” or “with all your strength do what God wants” or “set your mind on doing what God wants.”

The text that follows is literally “but as slaves of Christ, doing the will of God.” The writer is saying that it is God’s will that Christian slaves obey their masters; therefore since they, the slaves, are Christ’s slaves, they are bound to obey God’s will. It must be repeated that in the context of this letter the masters, the slave owners, are Christians; nothing is said in this letter about the duties of Christian slaves toward non-Christian masters (for which see 1 Peter 2.18-21).

The phrase as slaves of Christ may often be translated as “since you are slaves of Christ” or “because you are slaves of Christ your owner.” In many languages this clause will have to come earlier in the sentence, “Because you are slaves of Christ, you should do….”

Quoted with permission from Bratcher, Robert C. and Nida, Eugene A. A Handbook on Paul’s Letter to the Ephesians. (UBS Handbook Series). New York: UBS, 1982. For this and other handbooks for translators see here .