3 But before delivering you over to the Creed, I think it is well to make use at present of a short summary of necessary doctrines; that the multitude of things to be spoken, and the long interval of the days of all this holy Lent, may not cause forgetfulness in the mind of the more simple among you; but that, having strewn some seeds now in a summary way, we may not forget the same when afterwards more widely tilled. But let those here present whose habit of mind is mature, and who have their senses already exercised to discern good and evil, endure patiently to listen to things fitted rather for children, and to an introductory course, as it were, of milk: that at the same time both those who have need of the instruction may be benefited, and those who have the knowledge may rekindle the remembrance of things which they already know.
I. Of God.
Source: Catechetical Lectures (New Advent)