And the Jews say, ‘The Christians stand on nothing;’ and the Christians say, ‘The Jews stand on nothing;’ while they both read the same Book. Even thus said those who had no knowledge, like what they say. But Allah shall judge between them on the Day of Resurrection concerning that wherein they disagree. (Al Quran 2:114)
Many devout Christians still believe that Trinity is not only mentioned in the New Testament but also the Old Testament.
William Lane Craig is one of the leading Christian apologists and it is useful for the Unitarians to have his confession, which I have paraphrased a little, to keep it short: ‘If we Examine Trinity, through the lens of the Old Testament, it is not Believable!’
Rabbi Tovia Singer makes a good point about absence of Trinity in the Old Testament and Prof. William Lane Craig has no genuine answer as to why God confused and not give the complete picture of Divinity to the Jewish prophets for 2000 years before Jesus, may peace be on him. However, William Lane Craig, an expert and an articulate debater that he is, weaves a verbose response of confusing and not defined terms, to keep those who are indoctrinated into Triune understanding bewildered! The fact of the matter is that the term Trinity is not mentioned even in the New Testament.
For 2000 years before Jesus, the Jews never thought of Trinity, as in Craig’s own words there was no reason to, going by the Old Testament. So, how can Trinity be legitimate if none of the Old Testament Prophets preached it. Mind you, the Old Testament makes 75% of the Bible and the New Testament mounts to nothing if it is not preceded by the Old Testament and that was the reason, why the Christian Fathers included it in the canon of the Bible.
The Unitarians build their case on what is central and fundamental and explain away allegoric and peripheral in light of that and the Trinitarians do the exact opposite and no wonder their teachings give rise to countless contradictions and absurdities, some of which are highlighted in the articles linked below. One I would mention here, a literal son, who is co-eternal with his Father, as the Trinitarians will have us believe, is logically and philosophically, simply silly. The Father has to at some point in time father the literal son and predate him, otherwise the son is literally not a son! Additionally, even if Jesus was magically eternal before, when he died for three days and three nights by the Trinitarian, childish counting, he is not eternal anymore. The understanding of what the debaters are doing is certainly in light of a profound verse of the Holy Quran, from Sura Aal-e-Imran, as the Rabbi focuses on central and fundamental and William Lane Craig, like any other Trinitarian, obsesses over what is ‘susceptible of different interpretations.’ The Quran says:
He (Allah) it is Who has sent down to thee (Muhammad) the Book; in it there are verses that are decisive in meaning — they are the basis of the Book — and there are others that are susceptible of different interpretations. But those in whose hearts is perversity pursue such thereof as are susceptible of different interpretations, seeking discord and seeking wrong interpretation of it. And none knows its right interpretation except Allah and those who are firmly grounded in knowledge; they say, ‘We believe in it; the whole is from our Lord.’ — And none heed except those gifted with understanding. (Al Quran 3:8)
The Trinitarians choose to obsess over Jesus and God the Father, but seldom or infrequently trouble the Holy Ghost. In their obsession about the person of Jesus of Nazareth, the Trinitarian apologists choose to read the Triune God, every time the word ‘God’ is mentioned in the Old Testament, which is hundreds of times, but, for 2000 years before Jesus, none of the Jews ever read the word in Triune terms and understood only one God, who is God the Father, in the later Trinitarian Christian understanding.