After staying some time in Antioch, Paul suggests a return to the churches established in Galatia (15:36). This tour of established churches is not unexpected since Paul has already made a return trip through Derbe, Lystra, and Iconium for the purpose of continued development and encouragement of these churches.
The suggestion that John Mark re-join the ministry team results in a “sharp disagreement” (verse 37-38). Barnabas wants to have John Mark travel with Paul once again. Sometimes Barnabas is presented as acting like a protective uncle, hoping to give the young and inexperienced John Mark another “chance” to prove himself. While this makes good preaching, that is not the way Luke describes the disagreement between Paul and Barnabas.
Paul “did not think it wise” (NIV) since John Mark has already abandoned them once. The NIV’s translation is adequate, but the word has the sense of being “worthy” or even “suitable to an activity” (BDAG). This could be taken in a positive sense (Paul does not see John Mark as a good “fit” for his vision of the ministry team), or negatively, Paul sees John Mark as unworthy since he has already abandoned the ministry.
John Mark did not depart because he was afraid of the tough travels or potential persecution. Rather, Paul’s rather harsh words to the Jewish sorcerer Elymas on Cyprus was a bit of a shock and perhaps even the idea that gospel should go to a Gentile like Serguis Paulus was a theological error. Luke uses the Greek word ἀφίστημι (afistemi, aorist participle). This word can mean more than simply “depart,” it can have the sense of “fall away” or “become a backslider.” The word appears in Daniel’s prayer of confession (Dan 9:9) and LXX Jer 3:14 to describe “faithless Israel.”
More significantly, Luke used the word in the Parable of the Sower in Luke 8:13 to describe the seed which does not take root and “falls away” when persecution comes. Perhaps there is a hint here that John Mark was not quite “rooted” in Paul’s mission and when he experienced the theologically disturbing idea that Paul was going to turn to the Gentiles, he fell away.
The way Luke describes this disagreement is significant – Paul and Barnabas had a “sharp disagreement,” a word used for provoking one to “love and good works,” Heb 10:24, but also anger, exasperation, etc. The word appears in the LXX for “furious anger of the Lord” in Deut 29:27 and LXX Jer 32:37. Paul and Barnabas are in such a heated disagreement over John Mark that there is no solution other than to separate their ministries.
This is another chance to observe some diversity within the early church. Whatever the reason, John Mark disagreed with Paul and separated from him, then later Barnabas did the same thing. If John Mark and Barnabas represent the “Jerusalem Church,” then I think there is a hint here of serious tensions between the Pauline Mission and the style of ministry happening in Jerusalem.