We start with myth. This is story and as reasonable as stories are. Let’s say Greek philosophers begin to extract metaphysics from myths. Plato and Aristotle laid the rails for Jewish, Christian and Muslim reasoning about faith. Their approaches were different, although both used reason to arrive at the existence of a God, or Gods.
Plato held things in the world, including thoughts, to be representations of a more profound reality composed of Forms, which exist in the mind of God. He reasoned from the top down. Aristotle went the other way: bottom up. We observe many examples of things and create mental categories but these categories have no intrinsic reality. “Forms” don’t exist. God can be proved as a logically necessary first cause to account for what we observe.
Aristotle’s work was lost until about 1000 in the West, but Plato’s survived — thus, Neoplatonists like Plotinus, Dionysius, Augustine and Anselm. Because our world (matter) is a degraded, lesser version of the true reality embodied in the Forms, these people don’t believe any of us can really know God. It’s too far away from us. What we can see are shadows of reality such as human goodness and truth, which in turn point us toward perfect Goodness and Truth, which is God.
The Roman Christian apologist and lawyer Tertullian built on a passage in Paul to argue that Faith does not need Reason to justify it: “I believe because it is absurd.” Another Church Father, Clement of Alexandria, was more influential, pulling philosophy into the service of faith and sounding positively proto-Anselmian: “I believe in order that I may know.”
The great Augustine — most famous Neoplatonist ever — took the reasonable position that to the extent philosophy (logic, natural history, science) examines the Truth, it can not contradict theology, which does the same. There are not two realities, only one. However, Truth is not equally available to all and a Catholic church is needed to guide honest seekers.
Philosophers would generally call someone like Augustine a “compatibilist” — that is, believing that Reason and Faith are entirely compatible. Another extreme is represented by a very influential, originally misidentified 6th century poobah known as Pseudo-Dionysius. This guy felt that God was utterly, entirely other, that the best human reason can do is to make tentative, negative assertions about God, to know what It is not.
Then the Dark Ages. Then silence.