The problem is that “moved by the authority of Divine teaching confirmed by miracles”
is a belief in the first place. I don’t believe that the Catholic Church has divine authority, and I’ve never seen a miracle confirming the same. I see a human religious institution like any other.
I understand Aquinas as saying: “belief is assent to a teacher with divine authority confirmed by miracles, even if the content of the proposed beliefs are unintelligible to reason.” Fine, however, to consider a human institution as having that divine authority in the first place is itself a belief that would require another, superior divine authority to meet his own criteria of meritorious belief. You may respond that this authority is Jesus. That is all well and good, but I have no reason to suppose much about Jesus, because those who have told me about him are not trustworthy by any reasonable metric. They say such fantastic things that are so incredibly unlikely (and of which I cannot confirm they have true knowledge), that the meager evidence provided is simply insufficient.
I do not know Jesus. Never met him. I’ve heard lots of contradictory things about him, but he is no more real to me than Hannibal or Socrates. I’ve read fantastic tales about Hannibal, and I similarly have little reason to suppose that they are actual fact. For the same reason I don’t have a good enough reason to think Mohammed was God’s prophet, I don’t have a good enough reason to believe Jesus was God. For the same reason I do not believe “The Watchtower” speaks with the voice of God, I do not believe the same of the Catholic Church, or any other church.
Further, the kind of “belief” Aquinas is describing here is actually a mode of “obedience” rather than belief (at best). At worst, it is a mode of spiritual self-deception and self-destruction.
For instance, my wife has a PhD in math and I am unable to understand many of the propositions she understands as “true” because I do not have the requisite training or power of reason. I trust that these propositions are true because she is an expert. However, it can’t be said that I “believe them.” I merely suppose they are true and don’t pay it any further attention.
However, are the propositions of faith similarly esoteric and obscure, like abstract high level math? Should we trust the experts? When the priest says “this piece of bread is God, kneel and worship it,” should we mouth “Amen” though our common sense and intuition rage against something
prima facie false? I don’t know whether homologous lie groups can be interpolated over Hilbert space or whatever, but I have obvious reasons to suppose that bread is not God himself! My wife asks me to believe she has a true understanding of something that is not intelligible to me, and that is OK because it doesn’t ultimately matter. The church asks me to believe something obviously false about the most important things, and provides either no or seriously dubious evidence, and that is not OK!
On top of it, they make threats. “You better pretend to believe this, because you could die any second, and if you don’t believe, it is straight to eternal doom, do not pass Go, do not collect $200 for you!”
Anyway, to pretend to believe something just to escape the threat of punishment is to debase oneself and do violence to one’s own humanity. Feigned belief under threat of torture is not laudable humility, it is craven ignobility and should be scorned and shunned.