“Paul, an apostle of Jesus Christ by the will of God, and Timothy our brother, unto the church of God which is at Corinth, with all the saints which are in all Achaia:”
King James Version (KJV)
1:1 Timotheus our brother - St. Paul writing to Timotheus styled him his son; writing of him, his brother.
2Co 1:1Paul's Anxiety Over the Corinthian Church SUMMARY OF II CORINTHIANS 1: Salutations. Paul's Recent Danger in Asia. His Conscientious Sincerity in Preaching the Gospel at Corinth. An Answer to Those Who Criticized His Change of Plans in Coming. to Corinth. Paul, an apostle of Jesus Christ. See PNT "1Co 1:1". And Timothy [our] brother. Timothy had been sent to Corinth along with the First Letter (1Co 4:17) and had now returned to Paul. As he had so recently been on a special mission to Corinth, he joins in the salutation. With all the saints who are in all Achaia. That is, in the whole of Greece, Achaia being the Roman name of the province. Corinth was the Roman capital. Hence it seems that other churches already existed in the province. We know of two, Cenchrea (Ro 16:1) and possibly Athens (Ac 17:34).