The experience, practice and theology of conversion have engaged Methodists since the 1730s. The Wesleys' Methodism owed its shape and impetus, if not its origins, to a religious experience commonly (if not unanimously) labelled 'conversion' and it formed one strand within a broader religious renewal movement which emphasised the preaching and practice of conversion. For much of its subsequent history Methodism has sought, expected and prized the conversion of individuals. This evangelistic and practical emphasis has sometimes complemented and sometimes challenged endeavours to interpret personal religious experience in terms of biblical and systematic theology, pastoral psychology and ecclesiastical history.
The life-changing experience of the Wesley brothers in May 1738 has exercised historians and theologians, within and beyond Methodism, for many years, and the competing analyses, particularly of the Aldersgate episode of 24 May, reflect both fashions in scholarship and changing Methodist and ecumenical contexts. Thus John Wesley has been variously translated from a religion of law to a religion of grace; transformed from a rigid High Church Anglican and proto-ritualist into an outgoing evangelical; imbued with a deeper mystical spirituality; or granted a new confidence, based on an assurance of his acceptance by God. Whether or not the language of 'conversion' may justly be used for this experience, and if it may, what it denotes, has been much debated: in the nineteenth century by H.W. Holden, R. Denny Urlin and James H. Rigg; in the 1930s by Henry Bett, George Jackson and J. Ernest Rattenbury; and in the 1990s by such American scholars as Theodore Jennings, Randy Maddox and Kenneth Collins. Inevitably sometimes the ecclesiastical context and preoccupations of the scholar have had a greater bearing on the analysis of the Aldersgate experience than an understanding of the Wesleys in the wider setting of the eighteenth century evangelical revival.
Wesley expressed some reluctance to use the term 'conversion', pointing out to Bishop Lavington that 'it rarely occurs in the New Testament'. However, in his Dictionary he defined it as 'a thorough change of heart and life from sin to holiness' and he published over 130 detailed accounts of conversions in his Journal. This narrative approach, continued in the memoirs published in the Arminian Magazine and its successors, in Thomas Jackson's edition of the Lives of the Early Methodist Preachers and in innumerable subsequent biographies, places the Wesleys' Methodism in the mainstream of the broader evangelical movement. Evangelicals emphasised conversion as an experience to be sought, claimed and testified to by the individual and urged by the Church in its evangelism. Opinions differed as to whether it was sudden and instantaneous or gradual; early Methodist biographies showed a sometimes protracted process of spiritual awakening, but preachers and revivalists from the nineteenth century onwards tended to urge an immediate response to the gospel. Where the respondent was a well-known sinner, the local impact could be considerable, as Samuel Chadwick discovered at Stacksteads in 1882-83.
Theological treatments of the subject sometimes struggled to fit conversion into the classical categories of dogmatic theology. Richard Watson's Theological Institutes discussed the benefits of redemption, but did not deal explicitly with conversion. W. Burt Pope, on the other hand, defined conversion as 'the process by which the soul turns, or is turned, from sin to God, in order to its acceptance through faith in Christ', and was thus able to treat the topic briefly between an exposition of prevenient grace and a discussion of repentance and faith. J.S. Banks touched on the vexed question of the relationship between conversion and baptism, arguing in response to the teaching of baptismal regeneration that 'baptism notwithstanding, conversion is in most cases still necessary to a Christian life.' Twentieth century psychology opened up fresh fields of enquiry, inspiring Wilfred R. Wilkinson's Hartley Lecture Religious Experience. The Methodist Fundamental (1928) and the works of Sydney G. Dimond on the psychology of Methodism. The Senior Catechism of 1952 offered a concise definition of conversion: 'We are converted to God when we respond to His grace in repentance and faith.' The Catechism of 1986 left this definition largely unchanged: '[Conversion] is the change which God works in us as we respond to his grace in repentance and faith.'
[April 25 [1738, at Blendon Hall]. '… fell into a dispute whether conversion was gradual or instantaneous. My brother was very positive for the latter, and very shocking - mentioned some later instances of gross sinners believing in a moment. I was much offended at his worse than unedifying discourse. Mrs. Delamotte left us abruptly. I stayed, and insisted a man need not know when first he had faith. His obstinacy in favouring the contrary drove me at last out of the room.'
(MS Journal of Charles Wesley)