Concerning Catholic relations with Protestant communities , certain commissions were established to foster dialogue and documents have been produced aimed at identifying points of doctrinal unity , such as the Joint Declaration on the Doctrine of Justification produced with the Lutheran World Federation in 1999 . With respect to Catholic relations with Protestant communities , certain commissions were established to foster dialogue and documents have been produced aimed at identifying points of doctrinal unity , such as the Joint Declaration on the Doctrine of Justification produced with the Lutheran World Federation in 1999 .