First United Methodist Church of Douglasville 6167 Prestley Mill Rd, Douglasville, GA30134 Even before there was a Douglas County, Franklin Winn, a local preacher, held worship in neighboring homes around the…More area. Eventually a church was built two miles west of the present Douglasville city limit, called Flat Rock Church. In 1966 the church was opened at its present site on Prestley Mill Road. A new family life center was added and opened in February, 1989. First Baptist Church of Douglasville currently has a congregation of about 500 people.