This is basically a chance to capture philosophically what Chesterton learned from experience and belief, which is simply that reality is sacred. He analyzes this from two separate points of view, explaining that the universe has two modes that are paradoxically opposed, chaos and order, which the human experiences in two psychological modes: fear and adventure. He says the human wanderlust is evidence of religious beauty, and he feels that the narrative nature of human life is evidence of artistic design.
Furthermore, Chesterton feels that humans are built with associative and interpretive powers in their minds, stemming from natural processes perhaps, which drive humans to interpret reality looking for its meaning. Chesterton encourages transcendental religion, because he wants the individual to look at their own life as a work of sacred art, as if every human story were its own book of the Bible.
By focusing on the sacred nature of human experience, Chesterton strikes a humanist note, while still defending his own bias toward Christianity. He feels that Christianity is a religion that should be considered for its merit. Not only that, but in his view of the universe as art, the story of Christianity has much beauty in it, and therefore in his view, much sacred truth. However, his Orthodoxy stops there, just shy of stating beliefs about other world views. Instead of comparing Christianity to other religions, he explores the depths of one religion's beauty when taken seriously.