The following quote is taken from this article by David Mills. The article is a little bit long, but it had some very helpful insights.
Chief among the classics to be read, of course, are the Scriptures, read as if they were classic stories, without their stained-glass and Sunday school associations. You would read them, for example, without drawing simple dogmatic lessons, as if the stories were primarily illustrations for ideas you’ve gotten from the Catechism. You would also read them as if they were written by one author, connecting “what he says here” with “what he says there.”
And you will read as if these were not just good stories, but our family’s story, as if when we said “Abraham” we were saying “great-grandpa” and when we said “St. Paul” we were saying “your saintly uncle Paul, the genius.” This is harder to do, and is conveyed mostly in an attitude of possession and reverence, of the sort you have for your greatest and most interesting of ancestors.
Good stories read seriously and with enjoyment will help form a child’s imagination, and give it a shape it will never entirely lose, no matter what the child does when he grows older. But we would be foolish to rely on stories to do more than stories can. Wise Christian parents will immerse themselves and their children ever more deeply in the life of the Church, whose worship and teaching and charity and fellowship will be the most profound creator of the Christian imagination.