A comment on 1 Corinthians 16:15:
Since Stephanas and his household have assigned themselves or devoted themselves to the service of God’s people, it seems likely that Paul perceives them not only as the first converts as such but more especially as the core base of mature, long-standing believers: as those whose loyal work and witness holds promise of more believers to come, i.e., to be added to the Christian church in Achaia. This accords with Paul’s use of aparge in 15:20, 23. On the other hand, Rom. 16:5 does seem to speak of Epaenetus as the first convert (aparge) in the Province of Asia (NIV). If we combine the two ideas, embodying Paul’s special interest in Corinth, Stephanas appears as “co-worker … in founding a church” (Banks).115 Hence perhaps the two nuances should be combined: the first of more converts to come in Achaia.116
Fascinating quote from A. C. Thiselton’s NIGTC commentary on The First Epistle to the Corinthians (Eerdmans, 2000), p. 1338.
There’s much more in the NT about evangelism, missions, and church-planting than what today’s church has noted thus far. This is one small example.