Whether It Is Necessary for Salvation to Believe Explicitly in the
Trinity?
Objection 1: It would seem that it was not necessary for salvation to
believe explicitly in the Trinity. For the Apostle says (Heb. 11:6):
"He that cometh to God must believe that He is, and is a rewarder to
them that seek Him." Now one can believe this without believing in the
Trinity. Therefore it was not necessary to believe explicitly in the
Trinity.
Obj. 2: Further our Lord said (John 17:5, 6): "Father, I have
manifested Thy name to men," which words Augustine expounds (Tract.
cvi) as follows: "Not the name by which Thou art called God, but the
name whereby Thou art called My Father," and further on he adds: "In
that He made this world, God is known to all nations; in that He is
not to be worshipped together with false gods, 'God is known in
Judea'; but, in that He is the Father of this Christ, through Whom He
takes away the sin of the world, He now makes known to men this name
of His, which hitherto they knew not." Therefore before the coming of
Christ it was not known that Paternity and Filiation were in the
Godhead: and so the Trinity was not believed explicitly.
Obj. 3: Further, that which we are bound to believe explicitly of God
is the object of heavenly happiness. Now the object of heavenly
happiness is the sovereign good, which can be understood to be in
God, without any distinction of Persons. Therefore it was not
necessary to believe explicitly in the Trinity.
_On the contrary,_ In the Old Testament the Trinity of Persons is
expressed in many ways; thus at the very outset of Genesis it is
written in manifestation of the Trinity: "Let us make man to Our image
and likeness" (Gen. 1:26). Therefore from the very beginning it was
necessary for salvation to believe in the Trinity.
_I answer that,_ It is impossible to believe explicitly in the
mystery of Christ, without faith in the Trinity, since the mystery of
Christ includes that the Son of God took flesh; that He renewed the
world through the grace of the Holy Ghost; and again, that He was
conceived by the Holy Ghost. Wherefore just as, before Christ, the
mystery of Christ was believed explicitly by the learned, but
implicitly and under a veil, so to speak, by the simple, so too was
it with the mystery of the Trinity. And consequently, when once grace
had been revealed, all were bound to explicit faith in the mystery of
the Trinity: and all who are born again in Christ, have this bestowed
on them by the invocation of the Trinity, according to Matt. 28:19:
"Going therefore teach ye all nations, baptizing them in the name of
the Father, and of the Son and of the Holy Ghost."
Reply Obj. 1: Explicit faith in those two things was necessary at all
times and for all people: but it was not sufficient at all times and
for all people.
Reply Obj. 2: Before Christ's coming, faith in the Trinity lay hidden
in the faith of the learned, but through Christ and the apostles it
was shown to the world.
Reply Obj. 3: God's sovereign goodness as we understand it now
through its effects, can be understood without the Trinity of
Persons: but as understood in itself, and as seen by the Blessed, it
cannot be understood without the Trinity of Persons. Moreover the
mission of the Divine Persons brings us to heavenly happiness.
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