Why were the General Epistles written? The six New Testament epistles known as James; 1 and 2 Peter; 1 and 2 John; and Jude are not directed to any one person or specific branch of the Church. The first verse in each epistle indicates who the intended audience was:


  The General Epistle of James1. James, a servant of God and of the Lord Jesus Christ, to the
  twelve tribes which are scattered abroad, greeting.   
  
  The First Epistle General of Peter
  1. Peter, an apostle of Jesus Christ, to the strangers scattered
  throughout Pontus, Galatia, Cappadocia, Asia, and Bithynia,
  
  The Second Epistle General of Peter1. Simon Peter, a servant and an apostle of Jesus Christ, to
  them that have obtained like precious faith with us through the
  righteousness of God and our Saviour Jesus Christ:
  
  The First Epistle General of John ?
  
  The Second Epistle of John1. The elder unto the elect lady and her children, whom I love
  in the truth; and not I only, but also all they that have known the
  truth;
  
  The General Epistle of Jude1. Jude, the servant of Jesus Christ, and brother of James, to
  them that are sanctified by God the Father, and preserved in Jesus
  Christ, and called:


Besides the obvious answer that they were direction from God, for what purpose were they written? It would appear they were written as general counsel to everyone who may read them, but to whom were they delivered? Were the epistles copied and delivered to all of the churches? Were they carried by missionaries and delivered as sermons? Are there any records that tell us who these epistles were sent to, or where they were first read?
Introduction

From the excerpts below, the Letter of St. James was addressed to the Christians of the Diaspora, who lived outside Palestine among the Gentiles; the First Letter of St. Peter was addressed to Christian communities living in various parts of Asia Minor. the environment there was hostile, which meant that Christians' perseverance was at risk; the Second Letter of St. Peter is addressed to Christians in general; the First letter of St. John, the fact that addresses are not mentioned suggests that it was a kind of circular letter sent to a number of Christian communities; the Second letter of St. John is addressed to a local church, very probably one in Asia Minor. the Third Letter of St. John is addressed to a Christian called Gaius, and perhaps through him to a group of Christian faithful; and finally the letter of St. Jude does not specify whom it is addressed to, but it was probably written originally for Christians converts from Judaism.

While each letter has its own content and purpose and there is very little common to them all, St. Augustine says that they were written to refute errors which were beginning to raise their head.



Below follows the excerpts in detail.


  The Catholic Letters
  
  After the thirteen letters of St.Paul and the letter to the Hebrews
  come seven other letters (one by St. James, two by St. Peter, three by
  St. John and one by St. Jude) which since the time of Origen, Eusebius
  and St. Jerome have been known as the 'catholic' letters, letters to
  the Church at large, not directed to a particular church or
  individual: the second and third letters of St. John, even though they
  are addressed to a private individual are regarded as appendixes to
  his first letter and are also included in the 'catholic letters'
  category.
  
  Source: A GUIDE TO THE BIBLE | ANTONIO FUENTES


And also


  The Catholic Letters
  
  The canon of the books of the New Testament includes, along with the
  Pauline corpus (the thirteen letters of St. Paul and the letter of
  Hebrews), a group of seven others which Tradition usually calls the
  "Catholic Letters" - that written by St. James, two by St. Peter,
  three by St. John and one by St. Jude. Apparently the reason for
  grouping them together is not because they are similar in doctrine or
  style, but simply to distinguish them from the body of Pauline
  letters. This grouping already existed from around the end of the
  fourth century AD (cf. Eusebius of caesarea, Eccl. Hist., 3, 25,
  2-3). The books have not always been given this position in the New
  testament: the great Vatican and Siniatic codexes place them after the
  book of the Acts of the Apostles; from the time of St. Jerome onwards,
  all bibles place the immediately after the writings of St. Paul, just
  before the book of Revelation. Nor were they all in the same sequence
  as now: we often find St.Peter's two letters coming first; however,
  from St. Jetome onwards most manuscripts place them where they
  normally appear in printed bibles.
  
  The name "catholic" was applied by Origen to the First Letter of
  Peter, the first of John and that of Jude. Later Eusebius and St.
  Jerome extended the title to cover all seven letters. It seems that
  they were given this name because they were addressed to the whole
  Church and not to particular communities or persons, as St. Paul's
  letters were. By extension, the title was applied as to 1 and 2 John,
  even those letters were sent to specific individuals.
  
  Each letter has its own content and purpose and there is very little
  common to them all. St. Augustine says that they were written to
  refute errors which were beginning to raise their head (cf. De fide
  et operibus, 14, 21). Certainly, they all evidence the teaching and
  catechesis which was being given to the first communities of
  Christians. For most part, using pastoral tone, they deal with
  doctrinal instruction and moral teaching, all aimed at encouraging
  people to live deeply Christian lives.
  
  Source: THE NAVARRE BIBLE NEW TESTAMENT COMPACT EDITION


From the same Bible:


  The Letter of St. James
  
  Excerpt
  
  The letter is addressed to "the twelve tribes in the dispersion"
  (1:1), that is, the Christians of the Diaspora, who lived outside
  Palestine among the Gentiles. Anything we know about the circumstances
  in which it was written comes from the letter itself: that is, certain
  defects were beginning to appear which threatened the spiritual health
  of those communities. There is debate about the date of composition,
  but it was probably written in the 60s AD, although some scholars
  propose a later date.
  
  The First Letter of St. Peter
  
  Excerpt
  
  [...] the date of composition is usually put around the year 64 or 67,
  the possible years of Peter's martyrdom [...] It is addressed to
  Christian communities living in various parts of Asia Minor. the
  environment there was hostile, which meant that Christians'
  perseverance was at risk. many of them were converts from paganism,
  probably recent ones. Hence the constant reminders about Baptism [...]
  As we can see from the final greeting, the letter was written in
  "Babylon" (5:13), that is, Rome, the capital of the empire, as it used
  to be called symbolically [...]
  
  The main of the apostle seems to be to console Christians and exhort
  them to stay true to the faith in the midst of difficulties and
  persecution.
  
  The Second Letter of St. Peter
  
  Excerpt
  
  [...] internal analysis makes it more difficult to attribute the
  letter to Peter [...] the Tradition of the Church has associated the
  Second Letter of Peter with the person of the apostle.
  
  The letter is addressed to Christians in general, even though some
  expressions imply that it was originally addressed to Christian
  communities in Greece or Asia Minor. the dates of composition that
  have been suggested run from year 60 to the end of the first century.
  
  The letters of St. John 
  
  Excerpt
  
  The First Letter of John [...] the fact that addresses are not
  mentioned suggests that it was a kind of circular letter sent to a
  number of Christian communities. It is likely that it was written,
  after the fourth Gospel, to the Christian communities of Asia Minor
  mentioned in the book of Revelation (Rev 2:1-3:22). [...]
  
  The Second and Third Letters of St. John [...] In both letters the writer introduces himself as the "elder" (2 Jn 1; 3 Jn 1). The Second letter is addressed to the "elect lady and her children" (v. 1), a figurative way of referring to a local church, very probably on in Asia Minor. The Third Letter is addressed to a Christian called Gaius (v. 1), and perhaps through him to a group of Christian faithful. [...]
  
  The second Letter was written as a word of warning at a time when the danger from heretics was not as great as that revealed in 1 John. the counsel the writer gives is along the same lines as that contained in the First Letter. the Third Letter, although it does not contain new teachings, is valuable testimony to the fidelity of the early Christian communities and a model of type of letters of commendation mentioned elsewhere in the New Testament [...]
  
  The letter of St. Jude 
  
  Excerpt
  
  [...] The letter does not specify whom it is addressed to, but it was probably written originally for Christians converts from Judaism. We do not know when it was written; maybe around the year 70.
  
  The author seeks to exhort the faithful to put up a fight for the faith delivered to them (v. 3), reminding them that the apostles warned them in advance that ungodly people would appear on the scene, people given to licentiousness (vv. 17-18). maybe the author wrote the letter because he had learned that people like this had already wormed their way into those Christian communities (v. 4).