This is one of those questions where modern American debates have been imported into ancient Christian tradition. The Fathers were not biblical literalists in the modern sense.
What the Fathers actually said
St. Augustine (354–430) thought a literal six-day reading was too restrictive — he held that creation was instantaneous, with the "days" representing a structure of revelation, not chronology (The Literal Meaning of Genesis). St. Basil the Great preached on the days as actual days; St. Gregory of Nyssa took them more figuratively. Origen openly rejected woodenly literal readings. The Church accommodated all of this.
The Orthodox approach
Orthodoxy does not require any particular position on the age of the earth. What the Church does confess: God created freely, ex nihilo, out of love; creation is good; humans bear God's image; sin and death are intruders, not the original design. How long creation took is not a doctrinal question.
What Genesis is doing
Genesis 1 is structured liturgically — a hymn with refrains ("and God said," "and it was good," "evening and morning"). Three days of forming, three days of filling. It is teaching theology with surgical precision: one God (not many), transcendent (not part of nature), personal (speaks), and creation is ordered and good. Every clause is aimed at the polytheistic, chaos-worshiping cultures around Israel.
Science and Genesis
Stephen Meyer, John Lennox, Hugh Ross, and others have written extensively on how an old-universe reading harmonizes with the Big Bang and biology. Young-earth Christians like Todd Wood read the data differently. The Church has room for both as long as the theological claims of Genesis are preserved.
A pastoral word
If someone told you that you must choose between Genesis and science, they were offering you a false dilemma the Fathers never accepted. The God who wrote the Bible also wrote the world. You can love both books without fear.