With all your heart (Good News Translation) or “heartily” (Revised Standard Version) translates the Greek ek psuchēs “from the soul.” The reason Christian slaves should perform their duties in this manner is that they should consider their service as performed for the Lord Jesus Christ, and not only for their human masters.

In place of the phrase with all your heart, it may be more in keeping with the context to employ a phrase such as “with all your strength.”

Working for the Lord and not for men may be expressed as “working to help the Lord and not to help just men.”

Quoted with permission from Bratcher, Robert G. and Nida, Eugene A. A Handbook on Paul’s Letter to the Colossians. (UBS Handbook Series). New York: UBS, 1977. For this and other handbooks for translators see here .