Another letter (II Thess.) soon followed, giving more detailed advice.
As the field of Paul's activity broadened, he was obliged more and more
to depend upon letters, since he could not in person visit the churches
which he had planted. Questions of doctrine as well as of practice which
perplexed the different churches were treated in these epistles. To
certain of his assistants, like Timothy, he wrote dealing with their
personal problems. Frankly, forcibly, and feelingly Paul poured out in
these letters the wealth of his personal and soul life. They reveal his
faith in the making as well as his mature teachings. Since he was
dealing with definite conditions in the communities to which he wrote,
his letters are also invaluable contemporary records of the growth and
history of the early Christian church. Thus between 30 and 60 A.D.,
during the period of his greatest activity, certainly ten, and probably
thirteen, of our twenty-seven New Testament books came from the burning
heart of the apostle to the Gentiles.

[Sidenote: _Growth of the other epistles_]

Similar needs impelled other apostles and early Christian teachers to
write on the same themes with the same immediate purpose as did Paul.
The result is a series of epistles, associated with the names of James,
Peter, John, and Jude. In some, like Third John, the personal element is
predominant; in others, the didactic, as, for example, the Epistle of
James.

[Sidenote: _Purpose of the Epistle to the Hebrews_]

A somewhat different type of literature is represented by the Epistle to
the Hebrews. Its form is that of a letter, and it was without doubt