

Chapter 11. The Four Marks of the Church • 127
In the earliest professions of faith, the Catholic Church identified herself
as “one, holy, catholic, and apostolic.”We find these words in the Nicene
Creed professed at Sunday Mass. Traditionally, they refer to what are
known as the four marks of the Church, traits that identify the Church
before the world.
Inseparably linked with one another, these four marks indicate the
essential features of the Church and her mission on earth. Each mark is
so joined with the others that they form one coherent and interrelated
idea of what Christ’s Church must be. They strengthen the faith of the
believer and at the same time can attract non-Catholics to investigate the
Church more fully. Because of the sinfulness of the Church’s members,
these marks are not always lived out fully, so we need to view them as
both a reality and yet a challenge.
THE CHURCH IS ONE
The mark of oneness reflects the unity of the Trinity. The Holy Spirit, the
bond of love between the Father and the Son, unites all the members of
the Church as the one People of God. The Church professes one Lord,
one faith, and one Baptism and forms one body (cf. CCC, no. 866) under
the leadership of the Holy Father, successor to Peter the Apostle. Within
the Church there is a diversity of races, nations, cultures, languages, and
traditions, which are held together in one communion by the gift of love
from the Holy Spirit. The unity that Christ bestowed on his Church is
something she can never lose (cf. Second Vatican Council,
Decree on
Ecumenism
[
Unitatis Redintegratio
; UR], no. 4; CCC, nos. 813, 815).
Tragically, members of the Church have offended against her unity,
and throughout the centuries, there have developed divisions among
Christians. Already in the fifth century, doctrinal disagreements led to
the separation of some Christians in the eastern region of the Roman
Empire from the main body of the Church. More damaging was the
rupture between Rome and Constantinople in AD 1054. And in the six-
teenth century Western Europe experienced the divisions that followed
the Protestant Reformation.
The Catholic Church has always been committed to the restoration
of unity among all Christians. This commitment was intensified by the