This is more about how literal concrete operational faith can be.
The Quest of the Holy Grail (thirteenth century CE Britain, written in Norman French) tells the story of the knights of the Round Table, followers of King Arthur in Britain, who go out on a quest to find the Holy Grail after seeing a vision of it in Camelot. This is a spiritual quest rather than a literal adventure. Everything that happens to them is an allegory. Most of the knights fail to have very many adventures, mostly because they are not spiritual enough to find them. Some of the more famous knights do have adventures, but fail to achieve their goal because of their sinfulness. Only the purest of the knights, Galahad, Perceval and Bors, can succeed. Lancelot comes close, but his sinfulness in having had a twenty-four year affair with Guinevere the wife of King Arthur has tainted him beyond redemption, so even the most sincere repentance only allows him a partial vision of the Grail.
The following examples are taken from works (The Song of Roland, Records of the Western World, The Travels of Marco Polo) that are written at the level of concrete operations (Cerridwen’s stage 3a) and Kohlberg’s stage 3 of social and moral development. They would also fall into Fowler’s stage 3 of faith.
Concrete mysticism found its expression in the veneration of sacred objects (many of which were probably bogus tourist souvenirs), and sacred sites (many of which were probably also bogus).
Along with the cognitive developmental stages of Jean Piaget and the social/moral developmental stages of Lawrence Kohlberg (and also of Robert Selman), there is the research of James Fowler on stages of faith. Fowler’s stages of faith are not limited to people who follow an organized religion, or even any religion or spiritual practice at all. They’re more about the way a person sees the world, the way they go about believing in things—religious, spiritual or secular—than anything.