Authors:
A. W. Tozer (1897-1963) American pastor in The Christian and Missionary Alliance, and author of such Christian classics as The Pursuit of God and The Knowledge of the Holy.
Ambrose of Milan (c.339-397) one of the "Church Fathers" (teachers/theologians of the early church), bishop of Milan, defender against heresy, and mentor of Augustine of Hippo.
Anselm of Canterbury (c.1033-1109) Archbishop of Canterbury, scholar, philosopher and theologian; his most influential work is his book on the atonement, Cur Deus Homo (Why God Became Man).
Augustine of Hippo (354-430) bishop of Hippo in North Africa and one of the most influential of the "Church Fathers" (teachers/theologians of the early church)
Bernard of Clairvaux (1091-1153) French abbot and poet known for his piety and mysticism; influential in the spread of monasticism.
Blaise Pascal (1623-1662) influential French mathematician, physicist and philosopher.
C. S. Lewis (1898–1963) instructor at Oxford and Cambridge, theologian, apologist, and author of many books, including Mere Christianity and the beloved Chronicles of Narnia series for children.
Charles Wesley (1707-1788) early Methodist leader along with his brother, John Wesley; he wrote the lyrics for over 6000 hymns.
François Fénelon (1651 – 1715) French Roman Catholic Archbishop, writer, mystic, and defender of human rights.
Horatious Bonar (1808-1889) Scottish Presbyterian pastor, who was also a prolific author and hymn writer
J. I. Packer (b. 1926) British-born author and professor at Regent College in Vancouver, BC, Canada; considered one of the most important evangelical theologians of the late 20th century.
John Donne (1572-1631) English metaphysical poet who became an Anglican priest and Dean of St. Paul's Cathedral.
John Wesley (1703-1791) English Anglican clergyman, evangelist, and theologian who founded the Methodist movement.
Martin Luther (1483-1546) German monk whose teaching on justification by faith started the Protestant Reformation and founded Lutheranism.
Novatian (c.200-c.258) Roman theologian and writer; his most important work is On the Trinity (c.250); he was an antipope (rival pope) during a controversy on how to treat those who had denied their faith during persecution.
Oswald Chambers Oswald Chambers (1874-1917) Scottish pastor whose talks were complied by his wife into the popular devotional book My Utmost For His Highest.
R. C. Sproul (b. 1939) American theologian, pastor, teacher, and author who founded Ligonier Ministries.
Thomas Cranmer (1489-1556) English reformer, martyr, and Archbishop of Canterbury; chief writer/compiler/editor of the Book of Common Prayer.
William Carey (1761-1834) British missionary to India whose writing and example sparked an explosion of Protestant missionary effort in the English-speaking world and earned him the name "Father of Modern Missions."
Other Sources:
Ancient Liturgy - structured formats for public worship; in the early church, these were most likely modelled after services in Jewish synagogues.
Book of Common Prayer - Liturgical service book originating in the Church of England, partially based on earlier Roman Catholic liturgies; variations are used by other Anglican churches worldwide.
Hymns - A large selection of hymn lyrics and sound files can be found online at The Cyber Hymnal.
The Valley of Vision - The Valley of Vision: A Collection of Puritan Prayers & Devotions is a wonderful compilation of prayers by men like John Bunyan, David Brainerd, Charles Spurgeon, Isaac Watts, and Richard Baxter.