Who wrote letters to early christian communities?

Paul wrote letters to many churches. His letters are some of the books in the New Testament of The Bible

Romans= church of Rome

1st and 2nd Corinthians= church of Corinth

Galatians= church of Galatia

Ephesians= church of Ephasus

Phillipians= church of Phillipi

Colossians= church of Colosse

1st and 2nd Thessalonians= church of Thessalonica

Some other books of the Bible are Paul's letters. These letters were written to his friends and fellow apostles.

1st and 2nd Timothy= letter to Timothy

Titus= letter to Titus

Philemon= Paul's only private letter in the Bible; written to a friend about a runaway slave named Onesimus