Why the Catholic Church Has Priests: Connecting the Dots from the Old Testament

When people ask me about Catholic priests, I always start with the fact that Christ himself is the ultimate priest - everything flows from him. The Catechism puts it perfectly: "Christ is the source of all priesthood," and our priests "act in the person of Christ the head" (CCC 1548). But how did we get here from the Old Testament, and how does this relate to the priesthood that all Christians share? Let me walk you through it.

The Universal Priesthood in the Old Testament

This whole priesthood concept actually starts with God's original plan for all his people. At Mount Sinai, God told the Israelites: "You will be for me a kingdom of priests and a holy nation" (Exodus 19:6). This wasn't meant just for the Levites - it was God's vision for the entire people of Israel. Every single Israelite was called to be priestly in their relationship with God and the nations. This is our original identity from the garden. Who God created us to be.

But here's what happened: the golden calf incident showed that the people weren't ready for this universal priesthood. They needed intermediaries, structure, guidance. So God established the Levitical priesthood as a kind of scaffolding - not replacing his original vision, but providing what was necessary until the people could grow into it.

The prophets kept this universal vision alive. Isaiah spoke of Israel being "priests of the Lord" and "ministers of our God" (Isaiah 61:6). Jeremiah promised a new covenant where everyone would "know the Lord, from the least of them to the greatest" (Jeremiah 31:34). The universal priesthood was always the goal, not just an afterthought.

Aaron and the Levites - Ministerial Priesthood as Service

So when God established the Aaronic priesthood through Moses, it wasn't Plan B - it was a necessary step in the plan. These priests offered sacrifices, prayed for the people, and taught God's law, but they were always meant to serve the universal call of all Israel to be priestly.

The ceremonial aspects pointed forward to Christ, but those basic functions - sacrifice, intercession, teaching - they were preparing for something greater. As the Catechism says, Christian priests "make present sacramentally the one sacrifice of Christ" (CCC 1566), but they do this in service of the whole priestly people.

Melchizedek and figures like Samuel combined priestly, prophetic, and kingly roles, which is exactly what we see perfectly in Christ - and what all Christians are called to participate in.

Christ Fulfills Both Universal and Ministerial Priesthood

This is where it gets really beautiful. Jesus fulfills God's original vision - he creates a people who truly are "a chosen race, a royal priesthood, a holy nation" (1 Peter 2:9). Peter is directly echoing Exodus 19:6, showing that what God intended for Israel is now fulfilled in the Church.

But Jesus also establishes ministerial priesthood to serve this universal priesthood. At the Last Supper, he told the apostles to "do this in remembrance of me" (Luke 22:19). For Catholics, this isn't just about remembering - it's Christ instituting a ministerial priesthood to serve the priestly people. Then after his resurrection, he gives them the power to forgive sins (John 20:23), which serves the universal priesthood's need for reconciliation with God.

The Catholic Understanding: Two Ways of Participating in Christ's Priesthood

Here's where Catholics differ from many Protestants. We don't see the priesthood of all believers as eliminating ministerial priesthood - we see them as two complementary ways of participating in Christ's one priesthood.

The Universal Priesthood (Priesthood of All Believers): Every baptized Christian really participates in Christ's priesthood. The Catechism is clear: "The whole community of believers is, as such, priestly" (CCC 1546). This means:

The Ministerial Priesthood: Some are called to serve the universal priesthood in a special way through ordination. They "differ essentially and not only in degree" from the common priesthood (CCC 1547), but they exist to serve it, not replace it.

The Early Church Understood Both

The Church Fathers weren't confused about this distinction:

St. John Chrysostom really captured it in his work "On the Priesthood." He wrote: "The priest stands at the altar not representing his own person, but that of Christ" - but he also preached constantly about how all Christians are priestly through baptism.

St. Augustine helped develop the crucial distinction between these two participations in Christ's priesthood. He showed that all Christians are priests through baptism, while some serve this priesthood through ordination.

St. Jerome wrote extensively about how bishops and priests serve the whole Church, not just themselves: "Without the bishop, neither presbyter nor deacon can do anything" - but the bishop exists to serve the priestly people.

How This Works Practically

When I go to Mass, I'm not just watching the priest do something - I'm participating as part of the priestly people. The Catechism explains that "the faithful exercise their baptismal priesthood through their participation... in the Eucharistic sacrifice" (CCC 1273). The priest acts "in the person of Christ the Head," but the whole assembly offers the sacrifice together.

In my daily life, I offer spiritual sacrifices through my work, my relationships, my struggles - that's my universal priesthood in action. The ministerial priest serves this through:

Apostolic Succession Serves the Universal Priesthood

Through apostolic succession, there's an unbroken line from the apostles to today's priests. But this isn't about creating an elite class - it's about ensuring the universal priesthood is properly served. Ordination creates an "indelible character" that configures the priest to Christ (CCC 1563), but always in service of the whole priestly people.

It's Fulfillment of God's Original Plan

When I look at this development, I see God's original vision at Sinai finally coming to pass. Through Christ, we really do have "a kingdom of priests and a holy nation." But we also have ministerial priests who serve this universal priesthood, just like the Levites served Israel's calling to be priestly among the nations.

The New Testament doesn't eliminate the Old Testament understanding - it fulfills it perfectly. The universal priesthood that was promised to Israel becomes reality in the Church, while ministerial priesthood continues in a perfected form to serve this universal calling.

Why Both Matter

Some Protestants emphasize the priesthood of all believers to eliminate ministerial priesthood. Some Catholics focus so much on priests that they forget their own baptismal priesthood. But the Church Fathers and our tradition show us we need both.

The universal priesthood without ministerial service can lose its sacramental depth and apostolic connection. Ministerial priesthood without recognition of the universal priesthood can become clericalism. Together, they fulfill God's plan that was there from the very beginning at Mount Sinai: a people who are truly priestly, served by those specially called to make Christ's priesthood sacramentally present among them.

It's not arbitrary - it's the natural unfolding of God's plan that was there from the beginning, now fulfilled in Christ and continuing in his Church.