Methodism (from Greek: μέθοδος - methodos, "pursuit of knowledge") is a movement of Protestant Christianity represented by a number of denominations and organizations, claiming a total of approximately seventy million adherents worldwide. The movement traces its roots to John Wesley'sevangelistic revival movement within Anglicanism. His younger brother Charles was instrumental in writing much of the hymnody of the Methodist Church.George Whitefield, another significant leader in the movement, was known for his unorthodox ministry of itinerant open-air preaching. The Methodist Church is known for its missionary work, and its establishment of hospitals, universities, orphanages, soup kitchens, and schools to follow Jesus' command to spread the Good News and serve all people.

Wesley, along with his brother, founded the Holy Club while they were at Oxford, where John was a fellow and later a lecturer at Lincoln College. The holy club met weekly and they systematically set about living a holy life. They were branded as "Methodist" by students at Oxford who derided the methodical way they ordered their lives. Wesley took the attempted mockery and turned it into a title of honour. Initially Whitefield and the Wesleys merely sought reform, by way of a return to the gospel, within the Church of England, but the movement spread with revival and soon a significant number of Anglican clergy became known as Methodists in the mid-18th century. The movement did not form a separate denomination in England until after John Wesley's death in 1791. Although Wesley and the majority of his followers were decidedly Arminian in their theological outlook, George Whitefield, Howell Harris, and Selina Hastings, Countess of Huntingdon were notable for being Calvinistic Methodists, and the Presbyterian Church of Wales originated from the preaching of Harris and Whitfield.

John Wesley ( /ˈwɛzlɪ/; 28 June [O.S. 17 June] 1703 – 2 March 1791) was a Church of England cleric and Christian theologian. Wesley is largely credited, along with his brother Charles Wesley, as founding the Methodist movement which began when he took to open-air preaching in a similar manner to George Whitefield. In contrast to George Whitefield's Calvinism, Wesley embraced the Arminian doctrines that were dominant in the 18th-century Church of England. Methodism in both forms was a highly successful evangelical movement in the United Kingdom, which encouraged people to experience Jesus Christ personally.

Wesley's teachings, known as Wesleyanism, provided the seeds for both the modern Methodist movement, the Holiness movement, Pentecostalism, the Charismatic Movement, and Neo-charismatic churches, which encompass numerous denominations across the world. In addition, he refined Arminianism with a strong evangelical emphasis on the Reformed doctrine of justification by faith.

Wesley helped to organize and form societies of Christians throughout England, Scotland, Wales, North America and Ireland as small groups that developed intensive, personal accountability, discipleship and religious instruction among members. His great contribution was to appoint itinerant, unordained preachers who travelled widely to evangelise and care for people in the societies. Young men who acted as their assistants, known as "exhorters", emulated the twelve apostles after the ascension of Jesus.^{[citation needed]}