Declaration in Defence of the Catholic Doctrine on the Church against Certain Errors of the Present Day (Mysterium Ecclesiae)

For nearly 500 years, the Congregation for the Doctrine of the Faith (CDF) has defended the Catholic Church from internal heresy—whether by false teaching or malpractice of faith. It is the oldest of the Curia’s nine congregations, and is made up of cardinals, bishops, priests, lay theologians, and canon lawyers. According to Pope Paul VI’s 1965 Motu Proprio Integrae Servandae, “All questions which regard the doctrine on faith and morals or which touch upon the faith are within the competence of the Congregation … It examines new teachings and new opinions in whatever way they are spread, it promotes studies in this area, and encourages the Congresses of scholars; it condemns those teachings found to be contrary to the principles of the faith, after, however, having heard the view of the Bishops of those regions, if they are specifically connected with the issues.”