The Association of Vineyard Churches, also known as the Vineyard Movement, is a neocharismatic evangelical Christian denomination. The Vineyard Movement is rooted in the charismatic renewal and historic evangelicalism. Instead of the mainstream charismatic label, however, the movement has preferred the term Empowered Evangelicals (a term coined by Rich Nathan and Ken Wilson in their book of the same name) to reflect their roots in traditional evangelicalism as opposed to classical Pentecostalism. Members also sometimes describe themselves as the "radical middle" between evangelicals and Pentecostals, which is a reference to the book The Quest for the Radical Middle, a historical survey of the Vineyard by Bill Jackson. Membership requires that individuals serve in their church.