Suppose a person entering a house were to feel heat on the porch, and going further, were to feel the heat increasing, the more they penetrated within. Doubtless, such a person would believe there was a fire in the house, even though they did not see the fire that must be causing all this heat. A similar thing will happen to anyone who considers this world in detail: one will observe that all things are arranged according to their degrees of beauty and excellence, and that the nearer they are to God, the more beautiful and better they are.
"Sermon-Conferences of St. Thomas Aquinas on the Apostles' Creed". Book by Thomas Aquinas, 13-14, 2005.