General Information:

Here the he words "he" and "him" refer to Apollos

to pass over into Achaia

"to go to the region of Achaia." The phrase "pass over" is used here because Apollos had to cross the Aegean Sea to get to Achaia from Ephesus.

Achaia was a Roman Province in the southern section of Greece.

"fellow believers in Ephesus"

"wrote a letter to the Christians in Achaia"

"those who had believed in salvation by grace" or "those who by God's grace believed in Jesus"