The connection between ideas and actions is intimate and enduring. Because ideas have consequences, and because bad ideas have bad ones, it matters what you think. The differences between natural theology and authentically Christian theology lead, therefore, to differences in spirituality, and they are our focus.
I begin with an important and fundamental difference: the difference between the first mover and the first lover, or what Dante called “il primo Amore.”
If, in some degree, worlds reflect their makers, then consider this: A world in motion is far different from a world in love. Aristotle’s first mover is not, and cannot be, the first and greatest Lover, though Dante’s God can be the first mover, if we think of Love as spiritual motion, the way Dante does. For him, indeed, “love makes the world go round.” For Dante, God can be, and is, precisely that, the prime Lover, because Dante knows Christ, and knows the God revealed in Christ. Multi-personal, interpersonal, everlasting Love lies at the core of Dante’s world, but not Aristotle’s, even though Dante inherited much from Aristotle, he did not inherit a prime Lover. That had to come from elsewhere. Being an aloof, distant, abstract and sub-personal force, Aristotle’s god could not give rise to Dante’s. The chasm between the two gods and the two worlds they create is beyond mere difference. It is incompatibility. Mere motion, on the one hand, and righteous, self-sacrificial affection, on the other hand, must not to be confused or conflated. Neither must the Gods from which they spring.
Consider, too, the difference in spirituality that the character and commandments pertaining to the two Gods in view (if we can say that Aristotle’s god even has a character or imposes moral requirements): The difference is between (1) moving, and causing, on the one hand, and (2) loving, communing, incarnating, and self-sacrificing, on the other. As even a moment’s reflection makes plain, personality-less, morality-less, love-less, and word-less unmoved movers like Aristotle’s cannot give rise to the Divine Comedy or to the spirituality it entails. Much, very much, needs to be added to it before the piety of the Divine Comedy or the revamped heroism of Paradise Lost emerge. That “very much” is the Word become flesh, the incarnation of Christ.