The first mentioned in the Old Testament is that of David to Joab, sent by Uriah (2 Samuel 11:14); a usage perhaps borrowed from the Phoenicians, with whose king Hiram he was intimate. The king's seal was usually attached in token of authority, and to guard against anyone but the person addressed reading it (1 Kings 21:8-9). The seal was of clay impressed while moist (1 Kings 21:8-9; Job 38:14). "A writing came to Jehoram from Elijah" (2 Chronicles 21:12). Originally messages were sent orally (Genesis 32:3; Numbers 22:5; Numbers 22:7; Numbers 22:16; Numbers 24:12; Judges 11:12-13; 1 Samuel 11:7; 1 Samuel 11:9). Hezekiah had a system of couriers or posts to transmit his letters in various quarters; the plan especially prevalent in Persia (2 Chronicles 30:6; 2 Chronicles 30:10; Esther 8:10; Esther 8:14).

We read of his "spreading before the Lord" Sennacherib's letter (2 Kings 19:14). Sanballat's "open letter" was an infraction of the etiquette of the Persian court (Nehemiah 6:5). Jeremiah wrote to the captives in Babylon (Jeremiah 29:1-3). In the New Testament Luke begins both his "Gospel" and "Acts" in the form of a letter to Theophilus; but in substance both books are rather histories than epistles. Our Lord wrote no epistle, as that to Abgarus king of Edessa is most probably not authentic (Eusebius H. E., 1:13). His office was to enact the facts, and to fulfill the personal ministry, upon which the church was to be founded. The epistles are the inspired commentaries unfolding the truths in the histories, the Gospels, and Acts; just as the prophets interpret the spiritual lessons designed by God to be drawn from the Old Testament histories.

Twenty-one of the 27 New Testament books are strictly epistles. Three more are so in form: Luke, Acts, and Revelation addressed to the seven churches. Matthew, Mark, and John alone are not epistolary either in form or substance. Fourteen, including Hebrew, are by Paul; three by John; two by Peter; one by James; one by Jude. Paul dictated his to an amanuensis, authenticating them with his autograph at the close, wherewith be wrote the salutation "grace be with thee," or "the grace of our Lord Jesus Christ," etc. But, in order to show his regard to the Galatians, whom Judaizers tried to estrange, he wrote all that epistle himself in large characters, for so Galatians 6:11-12 ought to be translated, "ye see in how large letters I have written." The largeness of letters was probably owing to his weakness of sight (Galatians 4:15).

The words "I have written" ("wrote," egrapsa ) distinguished this epistle as written by himself from 2 Thessalonians 3:17, "I write," where he only writes the closing salutation. Philemon 1:19 shows that that epistle also was all written by Paul as a special compliment to Philemon; whereas the accompanying epistle to the Colossians (Colossians 4:18) has only "the salutation" so written, as also 1 Corinthians 16:21. In Romans 16:22 his amanuensis, Tertius, salutes in his own name. Peter's closing salutation is "peace be with you"; as Paul's is "grace," etc. John after Paul's death takes up his closing benediction, "the grace of our Lord Jesus Christ be with you all," at the end of Revelation.

In the beginning of most of Paul's epistles "grace and peace" are his opening greeting; in the pastoral epistles concerning ministers "mercy" is added, "grace, mercy, and peace" (1 and 2 Timothy and Titus), for ministers of all men most need mercy (1 Corinthians 7:25; 2 Corinthians 7:1). All the epistles besides Paul's are called "universal" or "general." This designation holds good in a general and not strict sense; for the 2 and 3 John are addressed to specific persons in form, though in substance they are general. The epistolary form of inspiration gives scope for free expression of personal affection, and conveys divine truth, progressively unfolded to us, as to Christian faith, worship and polity with a freshness, point, and communion of heart with heart, such as could hardly be attained by formal, didactic treatises.

Bibliography Information
Fausset, Andrew R. Entry for 'Epistle'. Fausset's Bible Dictionary. https://www.studylight.org/dictionaries/eng/fbd/e/epistle.html. 1949.

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Epistle