This Sunday is the Solemnity of the Most Holy Trinity. It’s hard to recognize the importance of Trinity Sunday after so many Sundays of Easter, then Ascension and Pentecost, but it’s one of the most important feasts of the year, what with the Holy Trinity being “the central mystery of Christian faith and life” (CCC 234). It also has special significance for priests because the relationships of the Trinity, in light of the Incarnation, take on a particularly priestly character.
In Romans 8:34, St. Paul tells us that it is “Christ Jesus who died, rather, was raised, who also is at the right hand of God, who indeed intercedes for us.” This is no surprise to us as Catholics. Christ is a priest and intercession is a major part of priesthood. How does it relate to the Trinity? St. Paul gives his answer in Hebrews 7:3, where he identifies the Old Testament figure Melchizedek as a sign of God the Son, and thus a priest. In so doing, St. Paul also implies that priesthood is a part of God the Son’s identity, even in the times of the Old Testament, prior to the Incarnation. Trinitarian theology tells us that God the Son receives His substance from the Father and returns it in love. Thus, they are consubstantial, meaning that they share the same substance without division. In becoming man and taking on the role of “a priest forever in the manner of Melchizedek” (Ps 110:4, cf. Hebrews 7:17), Christ continues as a priest to offer Himself, together with the Church joined to Him, to God the Father, in the Holy Spirit. Every priest ordained into Christ shares in this intercessory role.