Day 211: The One Priesthood of Christ

The redemptive sacrifice of Christ is unique, accomplished once and for all; yet it is made present in the Eucharistic sacrifice of the Church. the same is true of the one priesthood of Christ; it is made present through the ministerial priesthood without diminishing the uniqueness of Christ's priesthood: "Only Christ is the true priest, the others being only his ministers." CCC 1545

In today's reading, the Catechism discusses the one, true priesthood of Christ and the sharing in this priesthood by Catholic priests. Melchizedek (Gen 14:18) and everything the Old Covenant prefigured, find perfect fulfillment in the priesthood of Christ (Heb 6:20).

The Catechism Compendium summarizes this understanding of the Old Covenant prefiguring of Christ's priesthood:

This sacrament was prefigured in the Old Covenant in the service of the Levites, in the priesthood of Aaron, and in the institution of the seventy “Elders” (Numbers 11:25). These prefigurations find their fulfillment in Christ Jesus who by the sacrifice of the cross is the “one mediator between God and man” (1 Timothy 2:5), the “High Priest according to the order of Melchizedek” (Hebrews 5:10). The one priesthood of Christ is made present in the ministerial priesthood. “Only Christ is the true priest, the others being only his ministers.” (Saint Thomas Aquinas) (#324)

In the Catechism Companion, Vol II we find some commentary on how this relates to the New Covenant and Catholic priests today:

In the New Covenant, priests are referred to as fathers and are joined to Jesus' priesthood. Priests "act on behalf of men in relation to God, to offer gifts and sacrifices for sins" (CCC 1539)... The sacrifice of the Holy Eucharist re-presents the one sacrifice of Jesus at every Mass. Jesus is the one High Priest, and Catholic priests share in his priesthood. (p. 186) 

Finally, Dr. Brant Pitre has an interesting video tying the Old Covenant priesthood with that established by Christ in the New: