An epistle.
The earliest letter in the bible is the Letter by Paul to the church in Corinth.
Timothy was the pastor/bishop of the church at Ephesus. Paul's letters to Timothy were meant to encourage and teach the young pastor how a church is to be lead and the importance of solid doctrine in the church.
The Apostle Paul wrote most of the New Testament as letters to different churches. For instance: Galatians was written to a church in Galatia; Phillippians to a church in Phillippi; Corinthians to a church in Corinth, etc.
St. Paul wrote two letters to the church of Corinth, now known as 1 Corinthians and 2 Corinthians.
Margaret Mullett has written: 'Theophylacht of Ochrid' -- subject(s): Bishops, Byzantine letters, Church history, Correspondence, History and criticism, Orthodox Eastern Church 'Letters, Literacy and Literature in Byzantium'
Irving Spence has written: 'Letters on the early history of the Presbyterian Church in America' -- subject(s): History, Presbyterian Church in the U.S., Presbyterian Church in the U.S. (General), Presbyterian Church
The goverment doesn't encourage religious practice because we have a separation of church and state and a secular democracy.
Wayne Weible has written: 'Letters from Medjugorje' -- subject(s): Doctrines, Catholic Church, Apparitions and miracles, Spiritual life, Church history
Frank A. Beattie has written: 'Companion to the constitution of the Presbyterian Church (U.S.A.)' -- subject(s): Government, Rules and practice, Presbyterian Church (U.S.A.)
William J. Gatens has written: 'Victorian cathedral music in theory and practice' -- subject(s): Church music, Church of England
When the bible was written there were no church buildings, churches were groups of Christan believers and Paul wrote letters to these 'churches'.
William Liston has written: 'The service of the house of God according to the practice of the Church of Scotland' -- subject(s): Liturgy, Church of Scotland, Public worship