Shared ground
Acts 12:24–25 functions as a narrated pivot. After arrests, death, escape, and a ruler’s collapse, the narrator summarizes the net effect: “the word of God” is pictured as continuing to expand. Then the scene shifts back to Barnabas and Saul, who complete a concrete assignment of aid/service and move on, now with John Mark traveling with them.
What the text explicitly says is (1) the “word of God” grows and multiplies, and (2) Barnabas and Saul finish their mission/service and travel again, taking John Mark. The verses do not explain methods, strategies, or detailed outcomes; they highlight continuity and forward motion.
Where interpretation differs (only where needed)
The main question is the travel detail in v. 25: did Barnabas and Saul “return to Jerusalem” or “return from Jerusalem”? English translations differ because underlying wording and manuscript evidence are weighed differently. Either reading keeps the core point (they completed the service and then traveled), but it affects whether the story imagines them arriving at Jerusalem or leaving it at this moment.
A secondary question is what “the word of God grew and multiplied” most directly refers to. Some take it mainly as the spread and influence of the message; others hear it as shorthand for the growing number of people receiving it. The sentence itself foregrounds the message (“word of God”) rather than giving a headcount.
Why the disagreement exists
The travel-direction issue comes from small differences in ancient copies and how the Greek phrasing is understood in context. Readers also weigh the larger storyline (the famine-relief trip mentioned earlier in Acts 11:27–30 and the next mission movement) when deciding which direction best fits.
What this passage clearly contributes
These verses present the movement as resilient: opposition and political upheaval do not halt the spread of God’s message. They also tie “word growth” to ordinary logistics—aid delivery is completed, messengers relocate, and named individuals (John Mark) enter the traveling network. The text links theological momentum (“word of God” advancing) with organized human activity (service completed, travel undertaken), without collapsing one into the other.