Do you really think “ALL the Saints” believed in a literal reading Genesis? I’ve read many times that Saint Augustine (who by the way live 1600 years ago, long before Darwin, Big Bang cosmology and a host of others even came on the scene to question literal Genesis scientifically) anyway, Augustine ***did not ***think it a good idea to *assume *Genesis is literal. He wrote numerous times on it, one book is De Genesi ad litteram libri duodecim (i.e. “The Literal Meaning of Genesis”). Augustine took the view that everything in the universe was created simultaneously by God, and not in seven calendar days like a plain account of Genesis would require. He argued that the six-day structure of creation presented in the book of Genesis represents a logical framework, rather than the passage of time in a physical way, it would bear a spiritual, rather than physical, meaning, which is no less literal. One reason for his interpretation is the passage in Sirach 18:1, “he created all things at once”, which Augustine took as proof that the days of Genesis 1 had to be taken non-literally.
A well known quote from his The Literal Meaning of Genesis sums up what he thought of people who demanded Genesis MUST be literal;
Usually, even a non-Christian knows something about the earth, the heavens, and the other elements of this world, about the motion and orbit of the stars and even their size and relative positions, about the predictable eclipses of the sun and moon, the cycles of the years and the seasons, about the kinds of animals, shrubs, stones, and so forth, and this knowledge he hold to as being certain from reason and experience. Now, it is a disgraceful and dangerous thing for an infidel to hear a Christian, presumably giving the meaning of Holy Scripture, talking nonsense on these topics; and we should take all means to prevent such an embarrassing situation, in which people show up vast ignorance in a Christian and laugh it to scorn. The shame is not so much that an ignorant individual is derided, but that people outside the household of faith think our sacred writers held such opinions, and, to the great loss of those for whose salvation we toil, the writers of our Scripture are criticized and rejected as unlearned men. If they find a Christian mistaken in a field which they themselves know well and hear him maintaining his foolish opinions about our books, how are they going to believe those books in matters concerning the resurrection of the dead, the hope of eternal life, and the kingdom of heaven, when they think their pages are full of falsehoods and on facts which they themselves have learnt from experience and the light of reason? Reckless and incompetent expounders of Holy Scripture bring untold trouble and sorrow on their wiser brethren when they are caught in one of their mischievous false opinions and are taken to task by those who are not bound by the authority of our sacred books. For then, to defend their utterly foolish and obviously untrue statements, they will try to call upon Holy Scripture for proof and even recite from memory many passages which they think support their position, although they understand neither what they say nor the things about which they make assertion.