Venerable John Henry Newman, C.O., gave some catechetical instructions, of which the following notes survive:
First Article of the Creed
1. I have been many weeks engaged in explaining what the Creed is, what is the need of it, and similar questions. Now then at length we proceed to consider what it contains.
2. The first article begins, 'I believe in God,' or, as in the Nicene, 'I believe in one God.'
3. Explain what we mean by God, viz. the one being of beings, self-dependent, etc., all-powerful, could create infinite worlds, each more beautiful than the one before, with all other infinite attributes; yet what we know of Him is infinitely less than what we do not know.
4. Here, then, you see the Creed opens in mystery, and what is remarkable, though it is a point of faith, it is also a point of reason. Hence the heathen philosopher asked one, two, four, eight, etc., days to determine about God. Then in the Mass—tremunt potestates—the name of God not pronounced by the Jews. It is what every child understands, who prays to God, as far as the highest intellect.
5. Here you see what is meant by saying that faith is against reason, viz. above, because reason itself comes to truths which it cannot comprehend.
6. There is no article in the whole Catholic faith more mysterious than this, which is the elementary one—nay, which is the belief of nature, too, without grace, which Protestants hold.