Paul was last one chosen to be an Apostle of Jesus Christ. The story
of his work and travels is told in the last half of the book of Acts
(his conversion and calling as an Apostle are recorded in Act 9 & 22
& 26). At various times, during his travels he wrote letters
(Called “epistles”) to congregations and individuals, usually to
address some particular problem or situation facing the recipients.
In most of his letter's Paul follows the general pattern of explaining
a theological concept or principle and then applying those principles to
the actual day to day lives of his readers. Paul wrote thirteen letters
that have been preserved for us: