The priesthood of Jesus Christ, in which every Christian priest shares, is the source of holiness in the Church and the impetus for all evangelization. Through the ministry of the priest, Christ’s lay faithful are nourished with the Word of Life and the Bread of Life; their sanctification makes possible the sanctification of the world.
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The reverence and respect of the Catholic faithful for their clergy is directed, then, not toward the man himself but toward Christ who is the Priest of the new eternal covenant and toward the priesthood any man derives from Him and shares with Him.
Latin notions of the presbyterate (and its conflation with the priesthood of Christ) and sacrifice, and some clericalism probably are sufficient to explain the resistance to the "priesthood of the faithful" as being "Protestant."