I draw your attention to his passage on the Iconoclasts …
The Fathers who gathered for the second Council of Nicea knew that the heresy of the Iconoclasts was very dangerous indeed. The Iconoclasts failed to understand the difference between Christian icons and pagan idols. Christian icons are based on revelation, especially the ultimate revelation, the Incarnation: “The Word was made flesh.” Pagan idols are a deception, taught by human imagination at best, by demons at worst, to lure men away from the true God. Icons, on the other hand, are based on revelation, and point to the Truth. The true God is known only through the Son (John 14:6, 17:3). The Fathers at that Second Council of Nicea (787 AD) knew that if the Church rejected icons they would reject the iconic nature of revelation, the truth that the Word was made flesh. In time, they could refuse to believe in the Son, as he has been revealed through his human nature. In time, the knowledge of God could be lost, if the Iconoclasts were to prevail.
Iconoclasm had come from a new religion that had only recently appeared in human history (I John 2:18). The cruel god that Mohamed’s hordes proclaimed, as they ravaged and plundered the weak and defenseless, was the god of this Medieval desert unitarianism, the combination of all antichrists who had come before, be they Gnostic or Arian. This god cannot understand love, because he is not the One – Elohim of Israel, known more fully by the Church as “the Father and the Son and the Holy Spirit.” The doctrine of the Trinity teaches us that “God is love,” as St. John put it (I John 4:8,16). But, about a god who is one and only one, through and through, with no plurality of Persons in him, we cannot speak of love; rather of an emptiness, a void in which eternity knows no compassion. G.K. Chesterton contrasted the God of revelation against the god of Islam very well:
“To us Trinitarians (if I may say it with reverence) — to us God Himself is a society. It is indeed a fathomless mystery of theology, and even if I were theologian enough to deal with it directly, it would not be relevant to do so here. Suffice it to say here that this triple enigma is as comforting as wine and open as an English fireside; that this thing that bewilders the intellect utterly quiets the heart: but out of the desert, from the dry places and, the dreadful suns, come the cruel children of the lonely God; the real Unitarians who with scimitar in hand have laid waste the world. For it is not well for God to be alone.” [From Orthodoxy by G.K. Chesterton. (chapter VIII)