You know that fire is the cause of heat; and
yet the heat and the fire begin at the same time. Though we cannot
understand this mystery of the Father and Son, we must believe it on the
authority of God, who teaches it. First, second, and third person in the
Blessed Trinity does not mean, therefore, that one person was before the
other, or brought into existence by the other.

24 Q. Is the Father God?
A. The Father is God and the first Person of the Blessed Trinity.

25 Q. Is the Son God?
A. The Son is God and the second Person of the Blessed Trinity.

26 Q. Is the Holy Ghost God?
A. The Holy Ghost is God and the third Person of the Blessed Trinity.

27 Q. What do you mean by the Blessed Trinity?
A. By the Blessed Trinity I mean one God in three Divine Persons.

*28 Q. Are the three Divine Persons equal in all things?
A. The three Divine Persons are equal in all things.

29 Q. Are the three Divine Persons one and the same God?
A. The three Divine Persons are one and the same God, having one and the
same divine nature and substance.

Though they are one and the same, we sometimes attribute different works
to them. For example, works of creation we attribute to God the Father;
works of mercy to God the Son; and works of love and sanctification to
the Holy Ghost; and you will often find them thus spoken of in pious
books; but all such works are done by all the Persons of the Trinity;
because such works are the works of God, and there is but one God.

*30 Q. Can we fully understand how the three Divine Persons are one and
the same God?
A. We cannot fully understand how the three Divine Persons are one and
the same God, because this is a mystery.

"Fully"--entirely. We can partly understand it. We know what one God is
and we know what three persons are; but how these two things go together
is the part we do not understand--the mystery.

*31 Q. What is a mystery?
A. A mystery is a truth which we cannot fully understand.

"A truth," that is, a revealed truth--one made known to us by God or His
Church. It is a truth which we must believe though we cannot understand
it. Let us take an example. When a boy goes to school he is taught that
the earth is round like an orange and revolving in two ways, one causing
day and night and the other producing the seasons: spring, summer,
autumn, winter. The boy goes out into the country where he sees miles of
level land and mountains thousands of feet in height. Again he goes ou