The Methodist Church in Ireland: www.irishmethodist.org should not be ignored in your research. By the early nineteenth century, it had spread like wildfire throughout Ireland. Today it is the fourth largest denomination in all of Ireland.
Methodist beliefs arrived from England to Ireland. The chief founder and theologian was John Wesley (1703-91). However, he would remain within the Church of England. It’s easiest to think of the Methodists as reformers within the Anglican tradition, even if they were only tolerated.
The contributions of Methodism to world Protestantism is often underestimated. The chief contribution of Wesley was his doctrine on “Christian Perfection,” also termed “entire sanctification.” This was a process wherein Christians could obtain a perfection of love, through God sanctifying and transforming the believer. Where Methodists may have seen this as a life-long process, later movements such as the Holiness and Pentecostals, would see this as a second instantaneous religious experience.
The first separate Irish Methodist churches were not in Ireland but in the North American colonies as early as the 1780s. They would begin to emerge in 1817-18 as their own denomination in Ireland.
Many Methodist records can be found at the Public Record Office of Northern Ireland in Belfast. Another resource is the Wesley Historical Society located at Edgehill College in Belfast.
An excellent primer to research is Steven C. ffeary-Smyrl’s Irish Methodists – Where Do I Start? (2000). Another important work is the chapter “Methodist Records in Ireland,” in James Ryan’s Irish Church Records (1992). For historical research, Charles H. Crookshank’s three-volume History of Methodism in Ireland (1885-1888) is a classic. The impact of Irish Methodism in world Protestantism can be found in Taggart, Norman W. Taggart’s The Irish in World Methodism 1760-1900 (1986).
The Methodist Church would suffer membership losses due to immigration. Canada and America were prime areas. However, they literally went everywhere the Irish would settle.