The apostle Paul (1:1).

Approximately A.D. 60, before the Epistle to the Romans was written; see notes 1^1а and 3¹ in Acts 20.

Macedonia (2:13 and note ^2c; 7:5-6; 8:1; 9:2, 4).

The church of God in Corinth, with all the saints in the whole of Achaia (1:1).