"... faithfully and strenuously you should resist the heretics in defense of the only true and life-giving faith, which the Church has received - the apostles and imparted to her sons. For the Lord of all gave to His apostles the power of the Gospel, through whom also we have known the truth, that is, the doctrine of the Son of God: to whom also did the Lord declare: 'He who hears you, hears Me; and he who despises you, despises Me, and Him who sent Me' (Lk. 10:16)."