If I might rephrase the question, what I understand to question
to say is "What is unique about the Catholic Church?" Or perhaps
"What is found in the Catholic Church that is found in no other
Christian Church?
There are many ways I could attempt an answer. I could argue
that the Catholic Church was founded directly by Christ. I could
argue that within the Catholic Church are found the fullness of the
Graces of Salvation, and the fullest expression of Christian Truth.
However Protestant Christians would attempt to debate this, and
therefore I will not answer the question along those lines. I will
try to answer the question in such a way that Protestant Christians
would not debate the issue, but would rather agree.
There are two things which make the Catholic Church unique: The
Sacraments, in particular the Ministerial Priesthood, and the
Blessed Sacrament. These two "features" (for lack of a better term)
make the Catholic Church unique among any other Church which bears
the name Christian. Only in the Catholic Church can one encounter
the physical presence of Christ through the Blessed Sacrament.
Essentially Protestant Churches are defined by their rejection of
the physical presence of Christ in their communion services.
Protestants have a variety of views on the nature of the presence
of Christ, but all of them have in common a denial of a full
physical and bodily presence of Christ in communion. In short a
denial of the concept of Transubstantiation unites Protestants in
their varied "Eucharistic" theologies.
The Ministerial Priesthood is the second "feature" unique to the
Catholic Church. While the Catholic Church would affirm the
Priesthood of all believers which is received through the Sacrament
of Baptism, Catholics would also affirm another expression of the
Priesthood of Christ which is found within the Ministerial
Priesthood. In short, we can agree with the Protestants that there
is only one Priesthood which is possessed fully by our Lord and
savior Jesus Christ. However, this Priesthood of Jesus Christ is
shared with the Church in two ways: the Priesthood of the Baptized,
and the Ministerial Priesthood. And this is where we disagree with
Protestants. Protestants in addition to defining themselves by a
rejection of the Blessed Sacrament, also define themselves by a
rejection of the Ministerial Priesthood.
The Priesthood of the Baptized is a Sacrament of Sonship. This
is to say it is a priesthood which makes us adoptive sons of the
Father through the Sonship of Christ. The Ministerial Priesthood is
an expression of the Headship of Christ over the Church. Those men
who are called to serve in the Ministerial Priesthood are called to
be a Sacramental sign of Christ, and to exercise the headship of
Christ. At the essence of the Ministerial Priesthood is Sacrifice.
The role of the priest is to offer the atonement sacrifice. Because
Christ's Sacrifice is perfect and fulfills all other sacrifices, it
is the Sacrifice of Christ that the priest offers in the
celebration of Mass.
