In verse 8 in the fellowship of the Lord is literally “in the Lord” (similar to the meaning of “in Christ”; see 6.3, and 9-11).

My dear friend may be equivalent to “my close friend” or “my strong friend,” but the phrase in the fellowship of the Lord should not be understood as an expression of cause, as it is in a number of other contexts. In this particular verse it is equivalent to “he is my good friend and is in union with the Lord.”

Quoted with permission from Newman, Barclay M. and Nida, Eugene A. A Handbook on Paul’s Letter to the Romans. (UBS Handbook Series). New York: UBS, 1973. For this and other handbooks for translators see here .