The true faith compels us to believe that there is one holy catholic apostolic church, and this we firmly believe and plainly confess. And outside of her there is no salvation or remission of sins, as the Bridegroom says in the Song of Solomon: "My dove, my undefiled is but one; she is the only one of her mother, she is the choice one of her that bare her" [Song of Sol. 6:9]; which represents the one mystical body, whose head is Christ, but the head of Christ is God [1 Cor. 11.3]. In this church there is "one Lord, one faith, one baptism" [Eph. 4:5]. For in the time of the flood there was only one ark, that of Noah, prefiguring the one church, and it was "finished above in one cubit" [Gen. 6:16], and had but one helmsman and master, namely, Noah. And we read that all things on the earth outside of this ark were destroyed. This church we venerate as the only one, since the Lord said by the prophet: "Deliver my soul from the sword; my darling from the power of the dog" [Ps. 22:20]. He prayed for his soul, that is, for himself, the head; and at the same time for the body; and he named his body, that is, the one church, because there is but one Bridegroom [cf. John 3:29], and because of the unity of the faith, of the sacraments, and of his love for the church. This is the seamless robe of the Lord which was not rent but parted by lot [John 19:23]. Therefore there is one body of the one and only church, and one head, not two heads, as if the church were a monster. And this head is Christ and his vicar, Peter and his successor; for the Lord himself said to Peter: "Feed my sheep" [John 21:16]. And he said "my sheep," in general, not these or those sheep in particular; from which it is clear that all were committed to him. If therefore Greeks or anyone else say that they are not subject to Peter and his successors, they thereby necessarily confess that they are not of the sheep of Christ. For the Lord says in the Gospel of John, that there is one fold and only one shepherd [John 10:16]. By the words of the gospel we are taught that the two swords, namely, the spiritual authority and the temporal are in the power of the church. For when the apostles said "Here are two swords" [Luke 22:38]--that is, in the church, since it was the apostles who were speaking--the Lord did not answer, "It is too much," but "It is enough." Whoever denies that the temporal sword is in the power of Peter does not properly understand the word of the Lord when he said: "Put up thy sword into the sheath" [John 18:11]. Both swords, therefore, the spiritual and the temporal, are in the power of the church. The former is to be used by the church, the latter for the church; the one by the hand of the priest, the other by the hand of kings and knights, but at the command and permission of the priest. Moreover, it is necessary for one sword to be under the other, and the temporal authority to be subjected to the spiritual; for the apostle