Historical Trinitarian Quotes

The Old Testament tells us nothing explicitly or by necessary implication of a Triune God who is Father, Son and Holy Spirit.... There is no evidence that any sacred writer even suspected the existence of a [Trinity] within the Godhead.... Even to see in the Old Testament suggestions or foreshadowings or ‘veiled signs’ of the Trinity of persons, is to go beyond the words and intent of the sacred writers...The Jews never regarded the spirit as a person; nor is there any solid evidence that any Old Testament writer held this view. . . . The Holy Spirit is usually presented in the Synoptics and in Acts as a divine force or power. ... Although this spirit is often described in personal terms, it seems quite clear that the sacred writers never conceived or presented this spirit as a distinct person.

Fortman, Edmund J. (1972), The Triune God, Baker Book House, pp. xv, 8, 9.

"It must be admitted by everyone who has the rudiments of an historical sense that the doctrine of the Trinity, as a doctrine, formed no part of the original message. St Paul knew it not, and would have been unable to understand the meaning of the terms used in the theological formula on which the Church ultimately agreed".

Dr. W R Matthews, Dean of St Paul's Cathedral, "God in Christian Thought and Experience", p.180

"In order to understand the doctrine of the Trinity it is necessary to understand that the doctrine is a development, and why it developed. ... It is a waste of time to attempt to read Trinitarian doctrine directly off the pages of the New Testament".
R Hanson: "Reasonable Belief, A survey of the Christian Faith, p.171-173,1980

The doctrine of the Trinity is not taught in the Old Testament.
New Catholic Encyclopedia, 1967, Vol. XIV, p. 306.

The Old Testament can scarcely be used as authority for the existence of distinctions within the Godhead. The use of ‘us’ by the divine speaker (Gen. 1:26, 3:32, 11:7) is strange, but it is perhaps due to His consciousness of being surrounded by other beings of a loftier order than men (Isa. 6:8).
Davidson, A.B., Hastings Dictionary of the Bible, Vol. II, p. 205.

"The formulation ‘One God in three Persons’ was not solidly established, certainly not fully assimilated into Christian life and its profession of faith, prior to the end of the 4th century.... Among the Apostolic Fathers, there had been nothing even remotely approaching such a mentality or perspective"

New Catholic Encyclopedia, 1967, Vol. 14, p. 299.

It may startle those who are but acquainted with the popular writing of this day, yet, I believe, the most accurate consideration of the subject will lead us to acquiesce in the statement as a general truth, that the doctrines in question (viz., the Trinity and the Incarnation) have never been learned merely from Scripture.

Surely the sacred volume was never intended, and is not adapted to teach us our creed; however certain it is that we can prove our creed from it, when it has once been taught us. . . . From the very first, the rule has been, as a matter of fact, for the Church to teach the truth, and then appeal to Scripture in vindication of its own teaching.
Cardinal Newman, Roman Catholic - Arians of the Fourth Century (1833)

We are to consider the order of those persons in the Trinity described in the words before us in Matthew 28:19. First the Father and then the Son and then the Holy Ghost; everyone one of which is truly God. This is a mystery which we are all bound to believe, but yet must exercise great care in how we speak of it, it being both easy and dangerous to err in expressing so great a truth as this is. If we think of it, how hard it is to imagine one numerically divine nature in more than one and the same divine person. Or three divine persons in no more than one and the same divine nature. If we speak of it, how hard it is to express it.

If I say, the Father, Son and Holy Ghost be three, and everyone a distinct God, it is false. I may say, God the Father is one God and the Son is one God, and the Holy Ghost is one God, but I cannot say that the Father is one God and the Son is another God and the Holy Ghost is a third God. I may say that the Father begat another who is God; yet I cannot say that He begat another God.

I may say that from the Father and Son proceeds another who is God; yet I cannot say that from the Father and Son proceeds another God. For though their nature be the same their persons are distinct; and though their persons be distinct, yet still their nature is the same. So that, though the Father be the first person in the Godhead, the Son the second and the Holy Ghost the third, yet the Father is not the first, the Son the second and the Holy Ghost a third God.

So hard it is to word so great a mystery aright; or to fit so high a truth with expressions suitable and proper to it, without going one way or another from it.
Bishop Beverage, Private Thoughts, Part 2, 48, 49, cited by Charles Morgridge (1837), The True Believers Defence Against Charges Preferred by Trinitarians for Not Believing in the Deity of Christ. (Publisher: Boston: B. Greene.)

The subject of this fatal controversy, which kindled such deplorable divisions throughout the Christian world, was the doctrine of three Persons in the Godhead, a doctrine which in the three preceding centuries had happily escaped the vain curiosity of human researches, and have been left undefined and undetermined by any particular set of ideas.
J. L. Mosheim (D.D.), Lutheran, Ecclesiastical History (1863), from the translation by Murdock and Soames.

I ask with all humbleness where the idea of Threeness is expressed in the New Testament with a doctrinal sense and force? Where is the Triune God held up to be worshipped, loved, and obeyed? Where is He preached and proclaimed in that threefold character?

We read 'God is one,' as too, 'I and the Father are one;' but nowhere do we read that Three are one, unless it be in a text long since known to be interpolated. . . .

To me the whole matter is most painful and perplexing, and I should not even speak as I now do, did I not feel on the threshold of the grave, soon to appear before the Throne of all truth....Certainly not in Scripture do we find the expression 'God the Son,' or 'God the Holy Ghost.' Whenever I pronounce the name of God, simply, and first, I mean God the Father, and I cannot help meaning that, if I am meaning anything.
Reverend T. Mozeley, brother-in-law to Cardinal Newman, As quoted by H. A. Stannus (1882), in A History of the Doctrine of the Trinity in the Early Church.

My belief in the Trinity is based on the authority of the Church: no other authority is sufficient. I will now show from reason, that the Athanasian Creed and the Scripture are opposed to one another.

The doctrine of the Trinity is this:

-- There is one God in three persons; Father, Son, and Holy Ghost. The Father is God, the Son is God: and the Holy Ghost is God. Mind, the Father is one person, the Son is another person, and the Holy Ghost is another person. Now, according to every principle of mathematics, arithmetic, human wisdom, and policy, there must be three Gods; for no one could say that there are three persons and three Gods, and yet only one God. . . .

The Athanasian Creed gives the universal opinion of the Church, that the Father is uncreated, the Son uncreated: and the Holy Ghost uncreated -- that they existed from all eternity. Now, the Son was born of the Father; and, if born, must have been created. The Holy Ghost must also have been created, as he came from the Father and the Son. And, if so, there must have been a time when they did not exist.

If they did not exist, they must have been created; and therefore to assert that they are eternal is absurd, and bangs nonsense. Each has his distinct personality: each has his own essence. How, then, can they be one Eternal? How can they all be God? Absurd.

The Athanasian Creed says, that they are three persons, and still only one God. Absurd; extravagant! This is rejected by Arians, Socinians, Presbyterians, and every man following human reason. The Creed further says, that our Lord Jesus Christ is the Son of God and of man, 'not by conversion of the Godhead into flesh, but by taking of the manhood into God.' Now, I ask you, Did the Divinity absorb the manhood? He could not be at the same time one person and two persons. I have now proved the Trinity opposed to human reason.
Rev. James Hughes, Roman Catholic Priest, As quoted in Percy White's The Doctrine of the Trinity (1913.)

The Trinity is a mystery of faith in the strict sense, one of the “mysteries that are hidden in God, which can never be known unless they are revealed by God” (Dei Filius 4: DS 3015). To be sure, God has left traces of his Trinitarian being in his work of creation and in his Revelation throughout the Old Testament. But his inmost Being as Holy Trinity is a mystery that is inaccessible to reason alone or even to Israel’s faith before the Incarnation of God’s Son and the sending of the Holy Spirit.
Catechism of the Roman Catholic Church, Paragraph 237

People who adhere to sola scriptura (as they believe) often adhere in fact to a traditional school of interpretation of sola scriptura. Evangelical Protestants can be as much servants of tradition as Roman Catholics or Greek Orthodox Christians; only they don't realise that it is "tradition."
From Bruce's personal correspondence.
F. F. Bruce (M.A., D.D.), Evangelical Protestant

The Trinity is a mystery of faith in the strict sense, one of the “mysteries that are hidden in God, which can never be known unless they are revealed by God” (Dei Filius 4: DS 3015). To be sure, God has left traces of his Trinitarian being in his work of creation and in his Revelation throughout the Old Testament. But his inmost Being as Holy Trinity is a mystery that is inaccessible to reason alone or even to Israel’s faith before the Incarnation of God’s Son and the sending of the Holy Spirit.
Catechism of the Roman Catholic Church, Paragraph 237