John Wesley 
The Works of the Rev. John Wesley, Vol. 1 (of 32) [PDF ebook] 

John Wesley (17 June 1703 – 2 March 1791) was an English cleric, theologian and evangelist who was a leader of a revival movement within the Church of England known as Methodism. The societies he founded became the dominant form of the independent Methodist movement that continues to present.
Educated at Charterhouse and Christ Church, Oxford, Wesley was elected a fellow of Lincoln College, Oxford in 1726 and ordained as an Anglican priest two years later. He led the "Holy Club", a society formed for the purpose of study and the pursuit of a devout Christian life; it had been founded by his brother, Charles, and counted George Whitefield among its members. After an unsuccessful ministry of two years at Savannah in the Georgia Colony, Wesley returned to London and joined a religious society led by Moravian Christians. On 24 May 1738 he experienced what has come to be called his evangelical conversion, when he felt his "heart strangely warmed". He subsequently left the Moravians, beginning his own ministry.
A key step in the development of Wesley's ministry was, like Whitefield, to travel and preach outdoors. In contrast to Whitefield's Calvinism, Wesley embraced Arminian doctrines. Moving across Great Britain and Ireland, he helped form and organise small Christian groups that developed intensive and personal accountability, discipleship and religious instruction; most importantly, he appointed itinerant, unordained evangelists to care for these groups of people. Under Wesley's direction, Methodists became leaders in many social issues of the day, including prison reform and the abolition of slavery.
Although he was not a systematic theologian, Wesley argued for the notion of Christian perfection and against Calvinism—and, in particular, against its doctrine of predestination. He held that, in this life, Christians could achieve a state where the love of God "reigned supreme in their hearts", giving them outward holiness. His evangelicalism, firmly grounded in sacramental theology, maintained that means of grace were the manner by which God sanctifies and transforms the believer, encouraging people to experience Jesus Christ personally. His teachings are collectively known as Wesleyanism.
Throughout his life, Wesley remained within the established Church of England, insisting that the Methodist movement lay well within its tradition. In his early ministry, Wesley was barred from preaching in many parish churches and the Methodists were persecuted; he later became widely respected and, by the end of his life, had been described as "the best loved man in England". In 2002, he was placed at number 50 in the BBC's poll of the 100 Greatest Britons.