“We believe, teach, and confess that the sole rule and standard according to which all dogmas together with [all] teachers should be estimated and judged are the prophetic and apostolic Scriptures of the Old and of the New Testament alone, as it is written Ps. 119:105: Thy Word is a lamp unto my feet and a light unto my path. And St. Paul: Though an angel from heaven preach any other gospel unto you, let him be accursed, Gal. 1:8.”

Epitome of the Formula of Concord, 1