To those who followed the conversation this past week between myself and Nick with my Unitarian guests, you may have noticed me insisting several times over that Sir Anthony and others were “assuming Unitarianism”.
What does this mean? What was I getting at?
Martin Downes of the blog “Against Heresies” explains it well:
Some people struggle to accept that there is one God who eternally exists as three distinct persons. They see that statement and think “but that’s three Gods” (the heresy of tritheism), or they reduce the mystery to that of one God playing out three successive roles (the heresy of modalism), or else they consider one person (the Father) to be God and the other two persons to be creatures made by the will of God (the heresy of Arianism [or, Unitarianism]).
What categorical mistake unites these three errors? It is that God can only be one person [i.e. assuming unitarianism]. Why would we think that? Because when it comes to finite essences, finite beings, a second person demands that there be a second essence or being. That holds true for finite beings. With God we are dealing with an infinite being. The real question is, what has he actually told us about himself?
The Christian Church has confessed, on the basis of the Old and New Testaments, that there is only one true and living God, one being who is eternal, infinite and unchangeable, who is one in substance or essence, and three in persons. To quote Shedd again:
“The essence…is not prior to the persons, either in order of nature or of time, nor subsequent to them, but simultaneously and eternally in and with them”
The heresies of tritheism, modalism and Arianism [or, Unitarianism] have in common a non-negotiable commitment to think of God according to the measure of the fallen human mind. They are all afraid of infinitude. Doug Kelly, in the first volume of his systematic theology, cites some helpful words on this from T. F. Torrance, “the epistemological principle of the Arians [or, Unitarians] (was)…that what men cannot understand cannot be true.” That principle can only ever result in the embracing of heresy.
– via Against Heresies