376 THE UNITY OF THE CHURCH.
into heaven He left us, as it were, a vicegerent of His love . . . and so because Peter alone of all others pro- fesses his love he is preferred to all — that belrig the m ost ,;perfect he shoijld^.govern the^ more perfect.."*
These, then, are the duties of a shepherd: to place him.-, ^self as leader at the head of his flock, to fjrovide proper food for it, to ward off dangers, to guard against insidious foes, to defend^it against violence: in a word, to rule and govern it. Since therefore Peter has been placed as shep- herd of the Christian flock he has received the power of governing all men for whose salvation Jesus Christ shed His blood. "Why has He shed His blood? To buy the sheep which He handed over to Peter and his successors."*
And since all Christians must be closely united in the communion of one immutable faitli, Christ the Lord, in virtue of His prayers, obtained for Peter that in the ful- filment of his office he should never fall away from the faith. But I have asked for thee that thy faith fail not," ' and He furthermore commanded him to impart light and strength to his brethren as often as the need should arise: Confirm thy brethren.* He willed then that he whom He had designated as the foundation of the Church should be the defence of its faith. "Could not Christ, who con- fided to him the kingdom by His own authority, have strengthened the faith of one whom He designated a rock to show the foundation of the Church? " ^ For this reason Jesus Qhids±-.viilled that Peter should participate in certain names, signs of great things which properly belong to Himself alone: in order that identity of titles should show identity of power. So He who is Himself the chief corner-stone in whom all the building being framed
- S. Ambrosius, Exposit. in Evang. secundum Lucam, lib. x.
nn. 175,176.
" S. Johannes Chrysostomus, De Sacerdotio, lib. ii. 3 Luke xxii. 32.
- Ibid.
' S. Ambrosius, De Fide, lib. iv., n. 56.