To read the early church fathers is to immerse oneself into a world of theologians, preachers, and worshippers who were saturated in the Scriptures. Whatever we make of their exegetical methods, speculations, and odd pre-occupations, they self-consciously based their thinking upon the authority of the sacred text of the Word of God. Athanasius wrote that "The holy and inspired Scriptures are fully sufficient for the proclamation of the truth."
Whatever else may wish to discern as factors in their thinking (Hellenic allegorical methods of interpretation, strains of Platonic and Neo-platonic philosophy etc.) there can be no doubt as to their starting point; a point well recognised by O'Keefe and Reno in their refreshing primer Sanctified Vision: An Introduction to Early Christian Interpretation of the Bible:
How many times must we read and teach Origen's On First Principles, a dauntingly speculative inquiry into the nature of God, the world, human existence and destiny, before noticing that the opening sentence stipulates that the Bible is the sole source of wisdom?
To see that sentence and understand its meaning is like receiving a blow to the head.And to save you googling it, here is that sentence (and for good measure the one after it):
All who believe and are assured that grace and truth were obtained through Jesus Christ, and who know Christ to be the truth, agreeably to His own declaration, “I am the truth,” derive the knowledge which incites men to a good and happy life from no other source than from the very words and teaching of Christ.
And by the words of Christ we do not mean those only which He spake when He became man and tabernacled in the flesh; for before that time, Christ, the Word of God, was in Moses and the prophets. For without the Word of God, how could they have been able to prophesy of Christ?