Ecclesia semper reformanda est

Ecclesia semper reformanda est (Latin for "the church must always be reformed", often – as usual in Latin – shortened to Ecclesia semper reformanda) is a phrase first greatly popularized by Karl Barth in 1947, allegedly deriving from a saying of St. Augustine. It most often refers to the conviction of certain Reformed Protestant theologians that the church must continually re-examine itself in order to maintain its purity of doctrine and practice.