This article presents some well-articulated arguments for a Unitarian view of Scripture and God, published by Unitarian authors from the 19th century and onward:
A Statement of Reasons For Not Believing the Doctrines of Trinitarians, by Andrews Norton (1786-1853 AD) - Section III, pg. 77-78
Did they then believe their Master to be God, when, surprised at his taking notice of an inquiry which they wished to make, but which they had not in fact proposed, they thus addressed him? "Now we perceive that you know all things, and need not that any one should question you. By this we believe that you came from God." Could they imagine that he who, throughout his conversation, spoke of himself only as the minister of God, and who in their presence prayed to God, was himself the Almighty? Did they believe that it was the Maker of heaven and earth whom they were deserting, when they left him upon his apprehension? But there is hardly a fact or conversation recorded in the history of our Saviour's ministry which may not afford ground for such questions as have been proposed. He who maintains that the first disciples of our Saviour did ever really believe that they were in the immediate presence of their God, must maintain at the same time that they were a class of men by themselves, and that all their feelings and conduct were immeasurably and inconceivably different from what those of any other human beings would have been under the same belief.
A Statement of Reasons For Not Believing the Doctrines of Trinitarians, by Andrews Norton (1786-1853 AD) - Section III, pg. 79-82
But what have been stated are not the only consequences which must necessarily have followed from the communication of the doctrine in question. It cannot be denied by those who hold the doctrine of the deity of Christ, that, however satisfactorily it may be explained, and however well it may be reconciled with that fundamental principle of religion to which the Jews were so strongly attached, the doctrine of the Unity of God, yet it does, or may, at first sight, appear somewhat inconsistent with it. From the time of the Jew who is represented by Justin Martyr as disputing with him, about the middle of the second century, to the present period, it has always been regarded by the unbelieving Jews with abhorrence. They have considered the Christians as no better than idolaters; as denying the first truth of religion. But the unbelieving Jews, in the time of the Apostles, opposed Christianity with the utmost bitterness and passion. They sought on every side for objections to it. There was much in its character to which the believing Jews could hardly be reconciled. The Epistles are full of statements, explanations, and controversy relating to questions having their origin in Jewish prejudices and passions. With regard, however, to this doctrine, which, if it had ever been taught, the believing Jews must have received with the utmost difficulty, and to which the unbelieving Jews would have manifested the most determined opposition, - with regard to this doctrine, there is no trace of any controversy.
But if it had ever been taught, it must have been the main point of attack and defense between those who assailed and those who supported Christianity. There is nothing ever said in its explanation. But it must have required, far more than any other doctrine, to be explained, illustrated, and enforced; for it appears not only irreconcilable with the doctrine of the Unity of God, but equally so with that of the humanity of our Saviour; and yet both these doctrines, it seems, were to be maintained in connection with it. It must have been necessary, therefore, to state it as clearly as possible, to exhibit it in its relations, and carefully to guard against the misapprehensions to which it is so liable on every side. Especially must care have been taken to prevent the gross mistakes into which the Gentile converts from polytheism were likely to fall. Yet, so far from any such clearness of statement and fulness of explanation, the whole language of the New Testament in relation to this subject is (as I have before said) a series of enigmas, upon the supposition of its truth.
The doctrine, then, is never defended in the New Testament, though unquestionably it would have been the main object of attack, and the main difficulty in the Christian system. It is never explained, though no doctrine could have been so much in need of explanation. On the contrary, upon the supposition of its truth, the Apostles express themselves in such a manner, that, if it had been their purpose to darken and perplex the subject, they could not have done it more effectually. And still more, this doctrine is never insisted upon as a necessary article of faith; though it is now represented by its defenders as lying at the foundation of Christianity. With a few exceptions, the passages in which it is imagined to be taught are introduced incidentally, the attention of the writer being principally directed to some other topic; and can be regarded only as accidental notices of it. It appears, then, that while other questions of far less difficulty (for instance, the circumcision of the Gentile converts) were subjects of such doubt and controversy that even the authority of the Apostles was barely sufficient to establish the truth, this doctrine, so extraordinary, and so hard to be understood, was introduced in silence, and received without hesitation, dislike, opposition, or misapprehension. There are not many propositions, to be proved or disproved merely by moral evidence, which are more incredible.
A Statement of Reasons For Not Believing the Doctrines of Trinitarians, by Andrews Norton (1786-1853 AD) - Section III, pg. 83-84
The intrinsic difficulty of the doctrine in question is so great, and such was the ignorance of the first converts, and their narrowness of conception, that the Apostles must have continually recurred to it, for the purpose of explaining it, and guarding it against misapprehension. As a fundamental doctrine of our religion, it is one which they must have been constantly employed in teaching. If it were a doctrine of Christianity, the evidence for it would burst from every part of the New Testament in a blaze of light. Can any one think that we should be left to collect the proof of a fundamental article of our faith, and the evidence of incomparably the most astonishing fact that ever occurred upon our earth, from some expressions scattered here and there, the greater part of them being dropped incidentally; and that really one of the most plausible arguments for it would be found in the omission of the Greek article in four or five texts?
A Statement of Reasons For Not Believing the Doctrines of Trinitarians, by Andrews Norton (1786-1853 AD) - Section III, pg. 90-91
In the next place, I wish to recall another remark to the recollection of my readers. It is, that the doctrines maintained by Trinitarians, upon the supposition of their possibility and truth, must have been taught very differently from the manner in which they are supposed to be. Let any one recollect, that there is no pretense that any passage in scripture affirms the doctrine of the Trinity, or that of the double nature of Christ; and then let him look over the passages brought to prove that Christ is God; let him consider how they are collected from one place and another, how thinly they are scattered through the New Testament, and how incidentally they are introduced; let him observe that, in a majority of the books of the New Testament, there is not one on which a wary disputant would choose to rely; and then let him remember the general tenor of the Christian Scriptures, and the undisputed meaning of far the greater part of their language in relation to this subject. Having done this, I think he may safely say, before any critical examination of the meaning of those passages, that their meaning must have been mistaken; that the evidence adduced is altogether defective in its general aspect; and that it is not by such detached passages as these, taken in a sense opposed to the general tenor of the Scriptures, that a doctrine like that in question can be established.
Unitarian Christianity, by William Ellery Channing (1780-1842 AD), pg. 35-37
This doctrine, were it true, must, from its difficulty, singularity, and importance, have been laid down with great clearness, guarded with great care, and stated with all possible precision. But where does this statement appear? From the many passages which treat of God, we ask for one, one only, in which we are told, that he is a threefold being, or that he is three persons, or that he is Father, Son, and Holy Ghost. On the contrary, in the New Testament, where, at least, we might expect many express assertions of this nature, God is declared to be one, without the least attempt to prevent the acceptation of the words in their common sense; and he is always spoken of and addressed in the singular number, that is, in language which was universally understood to intend a single person, and to which no other idea could have been attached, without an express admonition. So entirely do the Scriptures abstain from stating the Trinity, that when our opponents would insert it into their creeds and doxologies, they are compelled to leave the Bible, and to invent forms of words altogether unsanctioned by Scriptural phraseology. That a doctrine so strange, so liable to misapprehension, so fundamental as this is said to be, and requiring such careful exposition, should be left so undefined and unprotected, to be made out by inference, and to be hunted through distant and detached parts of Scripture, this is a difficulty, which, we think, no ingenuity can explain.
We have another difficulty. Christianity, it must be remembered, was planted and grew up amidst sharp-sighted enemies, who overlooked no objectionable part of the system, and who must have fastened with great earnestness on a doctrine involving such apparent contradictions as the Trinity. We cannot conceive an opinion, against which the Jews, who prided themselves on an adherence to God's unity, would have raised an equal clamor. Now, how happens it, that in the apostolic writings, which relate so much to objections against Christianity, and to the controversies which grew out of this religion, not one word is said, implying that objections were brought against the Gospel from the doctrine of the Trinity, not one word is uttered in its defense and explanation, not a word to rescue it from reproach and mistake? This argument has almost the force of demonstration. We are persuaded, that had three divine persons been announced by the first preachers of Christianity, all equal, and all infinite, one of whom was the very Jesus who had lately died on a cross, this peculiarity of Christianity would have almost absorbed every other, and the great labor of the Apostles would have been to repel the continual assaults, which it would have awakened. But the fact is, that not a whisper of objection to Christianity, on that account, reaches our ears from the apostolic age. In the Epistles we see not a trace of controversy called forth by the Trinity.
Outline of the Testimony of Scripture Against the Trinity, by Henry Ware Jr. (1794-1843 AD), pg. 9-10
Let us consider, first, the language which is commonly used respecting our Lord Jesus. Is it such as implies that he is the same with Almighty God? Take his testimony respecting himself. - 'I came not to do mine own will.' - 'I can of myself do nothing.' - 'The Son can do nothing of himself.' - 'The Father that is in me, he doeth the works.' - He calls himself, 'he whom the Father hath sanctified and sent.' - He says, 'I am come in my Father's name.' And after his resurrection he says, 'I ascend to my Father and your Father, and to my God and your God.' - Ponder these expressions; weigh these words; and say whether they be the words of one who would represent himself as the independent God.
Take the testimony of the Apostles. 'Jesus of Nazareth, a man approved of God, by signs and wonders which God did by him.' - 'Appointed to be a Prince and Saviour' - 'at the right hand of God exalted' - 'made both Lord and Christ.' Because of his obedience unto death, 'God hath highly exalted him and given him a name above every name.' In the end he shall 'deliver up the kingdom to God, even the Father, that God may be all in all.' Weigh these expressions deliberately, and consider whether it be possible that they should be used concerning Almighty God. Yet such as these are applied to Jesus in every part of the New Testament.
Consider the terms of faith in him which were required of his disciples. Were they such as implied his supreme divinity? Remember the confession of Peter - 'Thou art the Christ, the son of the living God;' - and with this Jesus was satisfied. Remember the confession of Martha - 'I believe that thou art the Christ, the Son of God;' - and he required no more. Remember the reason which John gives for writing his Gospel; 'These are written that ye might believe that Jesus is the Christ, the Son of God.' Who does John say is born of God? 'Whoso believeth that Jesus is the Christ, is born of God.' Who does he say overcomes the world? 'He that believeth that Jesus is the Son of God.' What was the preaching of the Apostles? Look through the book of Acts, and you will find the burden of it to be, 'Reasoning from the Scriptures and testifying, that Jesus is the Christ.' Now is it possible, that, in all which is thus said of the necessity and value of faith in Jesus, - when believers were to be received into the church and their immortal interests were depending - is it possible that they should not have been required to believe him the Almighty God; if he were so? Would he and the Apostles have so solemnly assured them that faith in him as the Son of God was sufficient, if in truth he had been the very God?
One God, Three Persons, Four Views, Edited by C.A. McIntosh - Section I.4 (Dale Tuggy)
Fact 7: The New Testament pattern of worship and/or honor
As illustrated by Trinitarian liturgies, a Trinitarian worships God the Trinity, and also each of the divine "persons." But in the NT, the Trinity is never an object of worship; this is neither stated, nor implied, nor portrayed, nor presupposed anywhere. Neither is the Holy Spirit an object of worship. The main and ultimate object of worship is the Father, a.k.a. "God," whom we approach through Christ (Eph 5:20; Col 3:16-17; Heb 13:15). There is no attempt to spread around the worship equally between the three. Jesus, especially after his exaltation, is worshiped (or some would say honored) too, but the reason cited for this is not his divine nature but rather his exaltation by God because of his perfect, self-sacrificing service to God (Phil 2:9; Rev 5:9), and this worship of Jesus is explicitly said to be "to the glory of God the Father" (Phil 2:11). One would not expect God to be worshiped to the glory of someone above him!
Fact 7 is shocking given (the Trinitarian hypothesis). It is at most a little surprising given (the Unitarian hypothesis) (because the man Jesus is honored or worshiped in addition to God). Thus, Fact 7 confirms (the Unitarian hypothesis) over (the Trinitarian hypothesis).
Is Jesus Human and Not Divine?, by Dale Tuggy and Christopher Date - Section 9.3
When I cited Jesus's worship of and submission to God, Mr. Date offered the apologists' retort that of course being a man Jesus had to worship and submit himself to God (he couldn't be an atheist or a polytheist). This correctly assumes that any human must be a creature of God, but simply ignores that the one God of the Bible is subject to no one else, but rather all others are subject to him. Here, again following recent apologists, he is quick to accuse me of begging the question (assuming the very point at issue).
But noticing that Jesus worships and submits to another and calls him "my God" is not assuming the impossibility of someone being both human and divine. It is rather observing something which is (1) unsurprising if Jesus is God's human Messiah who is not divine, and (2) very surprising if Jesus is the one God. We would expect the one God, were he to be a man, to say "No one is god over me! I am God Almighty, the one true God, and all are subject to me!" We would not expect him to call someone else "the only true God" or to worship another, or to pray to anyone else, or to say that someone else is his god.
Divine Truth Or Human Tradition, by Patrick Navas - Chapter 1
Speaking more candidly in this regard, one Christian writer, after having examined the most problematic scriptural issues relating to the Trinitarian claim, wrote:
The thoughtful student must ask himself: If it was hard for the Jews in the early church to let go of the Law, wouldn't it have been even harder to get them to change their view of God? Fifteen New Testament chapters are dedicated to changing the Jew's mind on the Law. And if it took that much to deal with the Law, shouldn't we find at least 1 or 2 chapters explaining the change in how God would be viewed from now on? But not a single verse suggests the Jew change his view of God... [In our examination we noted the] lack of a single verse which 'taught' the doctrine. The Bible has many verses which 'teach' justification, 'teach' repentance, 'teach' baptism, 'teach' the resurrection, but not one verse in the entire Bible 'teaches' the doctrine of the Trinity. No verse describes it, explains it, or defines it. And no verse tells us to believe it.
Divine Truth Or Human Tradition, by Patrick Navas - Chapter 1
Expressing a very similar conviction, another Bible student of the nineteenth century wrote the following thought-provoking words in light of the traditional Trinitarian claim:
It seemed strange to me, that our compassionate Heavenly Father, who so well knew the weakness of human nature, should require us to receive a doctrine, violating the common laws of that very reason which he has given us, without such an explicit statement of it, and such an authoritative command for its reception, as would leave no possible chance for human reason to gainsay or resist it... I am firmly convinced that no doctrine can be necessary to salvation which is not so plainly revealed that the conscientious inquirer after the truth cannot possibly mistake it. 'Believe on the Lord Jesus Christ, and thou shalt be saved,' 'He that believeth that Jesus is the Christ is born of God,' - about these plain statements there can be no mistake. Here is a glorious platform on which sincere Christians of every name can meet, and exchange the right hand of fellowship.