From Pope St. John Paul II’s encyclical Fides et Ratio (1984):
The Acts of the Apostles provides evidence that Christian proclamation was engaged from the very first with the philosophical currents of the time. In Athens, we read, Saint Paul entered into discussion with “certain Epicurean and Stoic philosophers” (17:18); and exegetical analysis of his speech at the Areopagus has revealed frequent allusions to popular beliefs deriving for the most part from Stoicism. This is by no means accidental. If pagans were to understand them, the first Christians could not refer only to “Moses and the prophets” when they spoke. They had to point as well to natural knowledge of God and to the voice of conscience in every human being (cf. Rom 1:19-21; 2:14-15; Acts 14:16-17). Since in pagan religion this natural knowledge had lapsed into idolatry (cf. Rom 1:21-32), the Apostle judged it wiser in his speech to make the link with the thinking of the philosophers, who had always set in opposition to the myths and mystery cults notions more respectful of divine transcendence.
One of the major concerns of classical philosophy was to purify human notions of God of mythological elements. We know that Greek religion, like most cosmic religions, was polytheistic, even to the point of divinizing natural things and phenomena. Human attempts to understand the origin of the gods and hence the origin of the universe find their earliest expression in poetry; and the theogonies remain the first evidence of this human search. But it was the task of the fathers of philosophy to bring to light the link between reason and religion. As they broadened their view to include universal principles, they no longer rested content with the ancient myths, but wanted to provide a rational foundation for their belief in the divinity. This opened a path which took its rise from ancient traditions but allowed a development satisfying the demands of universal reason. This development sought to acquire a critical awareness of what they believed in, and the concept of divinity was the prime beneficiary of this. Superstitions were recognized for what they were and religion was, at least in part, purified by rational analysis. It was on this basis that the Fathers of the Church entered into fruitful dialogue with ancient philosophy, which offered new ways of proclaiming and understanding the God of Jesus Christ.
In tracing Christianity’s adoption of philosophy, one should not forget how cautiously Christians regarded other elements of the cultural world of paganism, one example of which is gnosticism. It was easy to confuse philosophy—understood as practical wisdom and an education for life—with a higher and esoteric kind of knowledge, reserved to those few who were perfect. It is surely this kind of esoteric speculation which Saint Paul has in mind when he puts the Colossians on their guard: “See to it that no-one takes you captive through philosophy and empty deceit, according to human tradition, according to the elemental spirits of the universe and not according to Christ” (2:8). The Apostle’s words seem all too pertinent now if we apply them to the various kinds of esoteric superstition widespread today, even among some believers who lack a proper critical sense. Following Saint Paul, other writers of the early centuries, especially Saint Irenaeus and Tertullian, sound the alarm when confronted with a cultural perspective which sought to subordinate the truth of Revelation to the interpretation of the philosophers.
— Fides et Ratio 36-37