After a month-long pause from my “serious” reading in order to read Harry Potter for the first time (and I will absolutely be reading it many times, because it is a simply fantastic series), I have taken up the Roman Catechism. Some readers may recall that the CCC takes its structure from this earlier work, dividing its subject matter among the heads of the Creed, the Sacraments, the Commandments, and the Lord’s Prayer. I have only just got started, but there are already bits that strike me as noteworthy either because of what they say or how they say it.
The Roman Catechism opens with some useful clarifying remarks about the nature of faith (this because the Creed opens with the words “I believe”). First of all, it makes clear the sense behind those two words I believe. When we say the Creed, we are not saying that we believe the things it contains in the sense of “I believe it is going to rain today,” or (even worse) “I believe I’ll have another piece of pizza.”
The word believe does not here mean to think, to suppose, to be of opinion; but, as the Sacred Scriptures teach, it expresses the deepest conviction, by which the mind gives a firm and unhesitating assent to God revealing His mysterious truths. [p. 14, available online here; emphasis in original]
This of course is nothing but the theological virtue of faith, and the RC goes on to identify certain characteristics associated with it. First, faith excludes doubt. Why? Because faith assents to what God has revealed precisely because it is God who has revealed it, and to doubt what He has revealed is to call into question its truth. If we question the truth of what He has revealed, then we are in effect suggesting that it is possible that He is either wrong or lying. But God cannot lie, and God cannot be mistaken. To doubt what He has revealed implies that God is evil or imperfect—that He is not actually God. May He deliver us from such sin! Let us say with a certain father, “I do believe, Lord. Help my unbelief” (Mark 9:23).
The second thing they say is that faith excludes curiosity. By this they mean to warn against the presumption implicit in thinking that God must justify to us what He says:
For when God commands us to believe He does not propose to us to search into His divine judgments, or inquire into their reason and cause…[H]ow rash and foolish are those who, hearing the words of God Himself, demand reasons for His heavenly and saving doctrines? Faith, therefore, must exclude not only all doubt, but all desire for demonstration. [ibid., p. 15]
If I suppose that God must explain Himself to me, I make myself His judge, or at least the judge of His Words. Can anything be more preposterous and scandalous than for a finite creature to pretend to sit in judgment of the infinite God?
Lastly, the RC says that faith requires open profession. If we genuinely assent to what God has said, then we ought to act like it. They quote various Scriptures to this effect, including Psalm 115:10 (“I have believed, therefore have I spoken”) and Romans 10:10: “For, with the heart, we believe unto justice: but, with the mouth, confession is made unto salvation.”
Aquinas, Etc. 
“The degree of loving is measured by the degree of giving.” ~ Edwin Louis Cole