From the BALTIMORE CATECHISM No. 3 FATHER CONNELL CONFRATERNITY EDITION
The Unity and Trinity of God
IMPORTANT TRUTHS ABOUT THE UNITY AND TRINITY OF GOD
Both reason and revelation assure us that there is, and can be, only one
God, for the very idea of the Supreme Being makes it impossible for God
to have an equal; but from revelation we learn that the one God is three
distinct Persons, known as the Father, the Son, and the Holy Ghost.
Before the coming of the Son of God this truth was not manifested even
to the Jews, although there are some texts in the Old Testament which
seem to imply that there is more than one Person possessing the divine
nature – for example: “Let us make man to our image and likeness”
(Genesis 1:26).
In his discourse at the last supper Our Blessed Lord mentioned the three
Persons by name, and He clearly spoke of the doctrine of the Holy
Trinity to the apostles just before He ascended into heaven. The texts of
Sacred Scripture containing these words of Christ have been given in this
lesson. There was also an external manifestation of the Holy Trinity at
the time of Our Lord’s baptism by St. John in the river Jordan. On that
occasion it was God the Son in His human nature who was baptized,
while God the Holy Ghost descended on Him in the form of a dove and
God the Father announced from heaven: “This is my beloved Son, in
whom I am well pleased.” (Matthew 3:17).
Hence, according to Catholic belief, there are three divine Persons but
only one divine nature. All three Persons are perfectly equal to each
other, because all possess the same divine nature with all its infinite
perfections. From all eternity the Son proceeds from the Father as the
Word, the product of the intellectual act whereby the Father understands
the divine nature; and the Holy Ghost proceeds from the Father and the
Son as the product of the act of love of these two Persons for the divine
goodness. All the actions of God outside of those whereby the second
and third Persons proceed are acts of the three Persons operating together
through the one divine nature. However, certain works performed by all
three Persons are appropriated or attributed to particular Persons as if
they individually performed them-for example, the work of creation to
the Father, the work of producing the human nature of Christ to the Holy
Ghost (Luke 1:35); but only the Second Person became incarnate.
Although the doctrine of the Blessed Trinity is a supernatural mystery-a
truth which we cannot discover by reason nor understand in the present
life-we believe it because it has been made known to us by God who can
neither deceive nor be deceived. Even in natural things there are many
mysteries which we accept on the testimony of our fellowmen. We
believe what the astronomers tell us about the stars and the planets,
although we cannot prove these truths ourselves. Not even the most
learned scientist understands fully the nature of the force we call
electricity; yet we all know that there is such a force and we
unhesitatingly accept the information that scientists give us about it. How
much more willing should we be to believe the marvelous truth which
God Himself has made known to us-that He is one in nature and three in
Persons-even though we cannot perceive this truth by our own reason
nor understand how each divine Person can be identical with the divine
nature, yet really distinct from the other two Persons!
On the first Sunday after Pentecost the Church celebrates a feast in honor
of the Most Blessed Trinity. Moreover, on Sundays outside of the
Christmas, Lenten and Easter seasons the Preface of the Holy Trinity is
recited or chanted in the Mass. One of the favored devotions of the
Catholic Church is the Doxology-the prayer: “Glory be to the Father and
to the Son, and to the Holy Ghost. As it was in the beginning, is now, and
ever shall be, world without end. Amen.” This Doxology is frequently
repeated in the official prayers of the Church, particularly in the Divine
Office which priests and the members of many religious orders recite
every day. And whenever we make the Sign of the Cross we profess our
faith in the mystery of the Most Blessed Trinity.
RESOLUTION: Whenever you recite the Doxology or make the Sign of
the Cross, try to remember that you are expressing your faith in the most
profound mystery of the Catholic religion, the mystery of the Most
Blessed Trinity.