The doctrine of the trinity describes an essential union of a divine and human nature, and a supposed union of three distinct created spirits:
They both confess, that there is no exact representation, no perfect example of any such union in nature, and yet they will be representing it over and over again; sometimes by a tree and its branches, sometimes by the sun and its light, sometimes by a mind and its faculties, sometimes by body and soul; and that nothing may be wanting in them towards the representation of it, they represent it at length by that which is not; an essential union of a divine and human nature, and by a supposed union of three distinct created spirits.
— Animadversions, Antitrinitarian Biography Vol I p. 273
Examining the Unions
The natural inquiry concerning the unions with-in the trinity Godhead is,
“How three (distinct, several, individual) divine beings, essences, or substances, should remain three several individual substances, and yet at the same time be united into one divine substance, called God?”—Howe, Calm and Sober Enquiry concerning the Possibility of a Divine Revelation, Antitrinitarian Biography Vol I p. 283
In order to try to comprehend the unions between the distinct spirits or substances we can summarize them by representing them as premises to an argument and examining them using logic.
The first premise being,
- FATHER is not SON
- SON is not HOLYGHOST
- HOLYGHOST is not FATHER
The second premise being,
And the conclusion of the argument being that God is a trinity.
- FATHER is God
- SON is God
- HOLYGHOST is God
However, such an argument is not structurally sound because the premises are not compatible with one another.
“Another structural feature of an argument that could render it fatally flawed would be one whose premises are incompatible with one another. And an argument that has such premises is one from which any conclusion, no matter how outrageous, can be drawn.”—T. Edward Damer, Attacking Faulty Reasoning
This can be more easily seen when the premises are simplified:
- FATHER is not SON is not HOLYGHOST
- FATHER is SON is HOLYGHOST
What the doctrine of the trinity is proposing is an argument where its two main premises contradict one another. If the doctrine of the trinity is a logical doctrine then both of the above premises when taken together would be true. However, it is not possible for both statements to be simultaneously true because they contradict one another and contradict a fundamental law of ontology, the Law of Noncontradiction.
“On what principle of philosophy, or by what rule of language, can it be correct to say, that the Father is a divine person, the Son is a divine person, and the Holy Ghost is a divine person, and therefore there are three divine persons; and yet, when it is asserted, that the Father is God, the Son is God, and the Holy Ghost is God, it should at the same time be denied, that there are three Gods?”—Two Letters touching the Trinity and Incarnation, Antitrinitarian Biography Vol I p. 240
Examining the Numbers
To try and restate the entire argument around numbers instead of persons we end up with the same result. Given no other information, what should the natural conclusion to these two premises be:
Premise 1: God is one
Premise 2: God is threeConclusion: ?
The natural conclusion is two conclusions taken together that are just as contradictory as the proposition:
Conclusion 1: God is one
Conclusion 2: God is three
In other words it is just as EQUALLY valid to draw from those two premises that God is three as it is to draw from them that God is one. If the conclusion of any argument for the number of God SHOULD BE that God is one, then any additional proposals or premises for any other number for God are irrelevant and the need for a doctrine to explain what God is one means is unnecessary. In other words, if the goal is to preach that God is one, why then confuse the minds of men with notions that God is anything other than one?
Aristole set forth the most fundamental principle of logic called the Law of Noncontradiction when he stated that, "it is impossible for anything at the same time to be and not to be."  Restated another way, "it is impossible that contradictory statements be simultaneously true."  The doctrine of the trinity violates this important principle because it attempts to be simultaneously that which it is and that which it is not.
One Yet Simultaneously Many
It is not logically possible according to the Law of Noncontradiction for God to be one spirit and simultaneously three distinct spirits; to assert otherwise would be to assert that the nature of God is contradictory in nature.
Can the human mind even comprehend a contradictory God existing as Indivisible and yet simultaneously Divisible; One yet Three? If we say that God is One and then say that that One is a unity of Three Somewhats, we have already broken down in thought our conceptualization of God as One.
“But what is it that is thus pretended to be impossible? ‘Tis but this, that there be Three Somewhats, which are but One God: and these Somewhats we commonly call Persons.”—Antitrinitarian Biography Vol I p. 208
“I now perceive that it has always been impossible to make one of three, or three of one, - one perfect and infinite being equal to three perfect and infinite beings. There may be gifted minds capable of comprehending this doctrine, but such is not mine. It is plain to me now that I have all my life been worshipping three distinct beings; never having been able, with the most strenuous efforts, to combine the three in my own mind so far as to form a simple idea.”—Mary Dana, Letters addressed to Relatives and Friends p. 2
In the study of parts, known as Merelogy, the ancient philosophers such as Aristole first developed part-whole reasoning with axioms such as "the whole is a sum of its parts". When that field of study and reasoning is applied to the trinity, the proposition that the trinity sets forth can be described as "the whole is a sum of its parts and each part is the whole sum".
However, such a proposition is only plausible if the remedial meanings of the words whole and part are abandoned and mystical ones take their place. In this mystification, the whole of God is likened to the Godhead and the parts of God are likened to Persons, Beings, Intellects, Spirits, Properties, Characteristics, Manifestations, Subsistences.
“They are so far from agreeing, that they are infinitely divided among themselves;... whether it be a Trinity of Minds, Essences, Somewhats, Attributes, Faculties, Modes, External Denominations, or what not, which is to be adored.”—Antitrinitarian Biography Vol I p. 288
Often times it is responded that the doctrine of the trinity does not violate the Law of Noncontradiction because the "sense" of the two premises of God being one and God being many are not equal. They say, in one sense God is one in essence and in another sense he is three in Persons. Such responses only try to circumvent the obvious contradiction by mystifying the distinction between the two premises and in doing so making the proposition harder to conceptualize.
Fully Human Yet Simultaneously Fully Divine
The primary claim of the trinity of a "supposed union of three distinct spirits" has over the course of Church history developed hand-in-hand with it's secondary claim of a "supposed union of divine and human natures" also known as the doctrine of the incarnation of Christ. However, an essential union of truly divine and truly human natures is an ontological and mereological impossibility as stated according to the antisemmetry postulate,
“Two distinct things cannot be part of each other.”—Achille Varzi, Stanford Encyclopedia of Philosophy: Merelogy
Opposite natures cannot be joined while remaining in opposition; a house divided cannot stand . The Scriptures state that God is spirit  and that man is flesh , which is to say, that the substance of God is incorruptible and the substance of man is corruptible. According to Paul, it is not possible for incorruption to wed corruption, and likewise neither can both incorruption and corruption simultaneously co-habit the same Being. Nor is it possible for the co-habitation of an infinite nature with a finite one. If the natures of God and man are so diabolically opposed it is therefore not possible for God to inhabit the body of a man or vice versa. Yet, this is the claim made by the doctrine of the trinity and incarnation: that two opposing, contradictory natures can co-exist simultaneously with-in the whole of God.
“On the other hand, the small number of texts which are brought forward as evidence of the deity of our Lord, can be explained without doing such violence to our reason, as the doctrine of two complete natures in one person – one infinite and the other finite – always must.”—Mary Dana, Letters addressed to Relatives and Friends p. 6
It is important to understand the doctrine of the trinity because it claims to describes "who" and "what" God is. Yet, even today the trinity is classified as a mystery of the Christian faith . To try and better understand this mystery, we can take a look at its origins or rather the introduction of it into the Christian religion by the early "church fathers".
“The first corruptions of Christianity were derived from heathenism, and especially from the principles of the oriental philosophy.”—Joseph Priestley, An History of the Corruptions of Christianity p. 205
Many of the early church fathers read the philosophies of Plato.
“Platonism influenced Christianity through Clement of Alexandria and Origen, and the Cappadocian Fathers. St. Augustine was heavily influenced by Platonism as well.”—Wikipedia, Platonism
By the third century Plato's teachings were combined with mysticism to form Neoplatonism and at the First Council of Nicaea 325 A.D were canonized along with the doctrine of the trinity.
“In the third century, Plotinus recast Plato's system, establishing Neoplatonism, in which Middle Platonism was fused with mysticism.”—Wikipedia, Platonism
“The link between mysticism and the vision of the Divine was introduced by the early Church Fathers, who used the term as an adjective, as in mystical theology and mystical contemplation.”—Wikipedia, Christian Mysticism
“The doctrines of the Trinity and Incarnation have no solid or good foundation in revelation or scripture... They are of paganick or heathen descent and origin, and were introduced into the Church by Platonick philosophers, when they came over to Christianity.”—Arthur Bury, The Naked Gospel, Antitrinitarian Biography Vol I pp. 238-239
In 600 A.D. the impossibility of the doctrine of the trinity and the abuses of the Church gave rise to the Muslim religion.
“As the Trinity, when first brought into the Church by the Platonists, did, by its natural absurdity and impossibility, give a check and stop to the progress of the gospel; so ever since it has served to propagate Dieism and Atheism, and to hinder the conversion of the Jews and Mahometans and the heathen nations not yet turned to Christianity.”—Arthur Bury, The Naked Gospel, Antitrinitarian Biography Vol I pp. 238-239
Even after the reformation many reformed churches still held a belief in the doctrine of the trinity. It was not until the age of enlightenment and founding of the United States that this belief was fully exposed.
“It is too late in the day for men of sincerity to pretend they believe in the Platonic mysticisms that three are one, and one is three; and yet that the one is not three, and the three are not one... But this constitutes the craft, the power and the profit of the priests.”—Thomas Jefferson to John Adams 1813
The doctrine of the trinity and the scriptures themselves oppose one another. If the scriptures are the revelation and light of God then the trinity has no place in them because the trinity is still a secret, it is still a mystery - it serves no purpose other than to confuse the minds of men. If logic is consistency and noncontradiction then paradox is the opposite: inconsistency and contradiction. As has been shown so far, the trinity is a contradiction, or rather a paradox and it is mysticism, through experience, that embraces paradoxes, ambiguities, and contradictions .
If God is a trinity, and the trinity is a mystery, then it can be logically concluded that those that worship the triune God worship what they do not know.
“What the mystical divines teach, cannot be called an explication; they deny all explications; we must say therefore ‘tis Samaritanism; for what our Savior says of the Samaritans, by way of reproof and blame, that these gentlemen profess concerning themselves, that they worship they know not what."”—Antitrinitarian Biography Vol I p. 265
If a man worships what he does not know, then it is not ever possible for him to come to a knowledge of what he worships. But we know in the Scriptures that it is possible to come to a knowledge of God . The dispute is not whether or not God is completely knowable, the dispute is whether or not he exists as a contradiction which it is not even possible to come to the knowledge of.
In three-valued logic there exists three truth values, true, false, and indeterminate . Since the logic of the trinity does not evaluate to a true proposition or a false proposition, it can therefore be classified as an unknown. Paul said of the unknown God:
“I found also an erection on which had been inscribed: To God—unknown; whom, therefore—not knowing—ye do worship, this One I announce to you.”—Acts 17:22 YLT
The scope of the trinity is outside of the bible because no where does it plainly and clearly teach that God is a trinity. If it were an essential doctrine that God should exist as a singleton and at the same time exist a composition, reason demands that an explication should be given by Christ or his Apostles, yet there is no single chapter dedicated to the topic. Even though the argument has been used many times before and is often scoffed at by the orthodox -- the word trinity cannot even be found in the bible. And neither will you find the terms God the Son, or God the Holy Ghost. Out of all the 66 books of the bible not once will you find any of those terms mentioned. The only support that the trinity has found for itself in the Scriptures is found through inference, allusion, and translational bias.
The ramification of the doctrine of the trinity is that Christ is God Almighty, but if that were the case then:
- God would have died at that hand of man
- God would have anointed God
- God would have raised God up
- God would have received God into heaven where he already existed
- God would sit God at his own right hand 
- God would be his own high priest 
- God would be both the mediated and the mediator between God and man
Christ was a man and there are many instances in the scripture where he is called such. He walked the earth with the same nature, in personhood, that every man has. He differed only in his nature according to his actions, which were divine -- in that he did the works of God -- and in this alone did he display the nature of God. His soul did not pre-exist his body in the same way that our souls do not pre-exist our own bodies. He was separate from God in substance in the same way that we are separate from God in substance. He was made of a corruptible body in the same way that we are made of a corruptible body. The scriptures depict him shedding that corruptible body in honor of God and being rewarded by God with an incorruptible body and further made the lord over all things under God.
“For there is one God, and one mediator between God and men, the man Christ Jesus;”—1 Timothy 2:5 KJV
I must say that if it weren't for the supposed notion of souls the scriptures would appear much less confusing and the doctrine of the trinity probably would not have been conjured up to explain the confusion.
BiblicalUnitarian provides refutations of all passages used to infer the doctrine of the trinity.
The Racovian catechism was written during the time of the reformation when men and women who held non-trinitarian beliefs were persecuted even by reformers.
Letters addressed to relatives and friends by Mary Dana is her explanation to family and friends about her conversion away from trinitarian beliefs.
- Vallicella, Bill. Is The Doctrine of the Trinity Logically Coherent?
- Aristole M 4.4.1006a
- McDowell, Josh. The New Evidence That Demands A Verdict pp. 600-601. Regis, E. 388-89.
- Mark 3:25
- John 4:24
- Genesis 6:3
- Wikipedia. Trinity
- McDowell, Josh. The New Evidence That Demands A Verdict p. 647
- O'Brien, Barbara. The Paradox of Paradoxes
- Colossians 1:10
- Wikipedia. Three-valued logic
- Ephesians 1:20
- Hebrews 6:20
- 1 Timothy 2:5