The issue is not that OECs have a "weak faith," but we believe we are taking a more appropriate view of the scripture. Indeed, if the text is indeed written metaphorically (as we believe), then reading it literally is the weaker position.
If you don't want to read my rather long (yet still way too short to pay true justice to this topic) answer, I suggest jumping down to my Conclusion section, for a summary of why I believe the OEC view pays proper respect to scripture, and is the logical view.
The basic arguments (that I'm aware of) to support the OEC interpretation of Genesis, are:
1. Character of God
As I touched on in this answer:
First, an important Biblical principle is found in Psalm 19:1:
The heavens declare the glory of God;
the skies proclaim the work of his hands.
God is revealed through His creation.
Second, from Hebrews 6:18:
...it is impossible for God to lie...
Together, I take this to mean that God's creation, and his scripture must be reconcilable. Any (good) science will not contradict any (good) interpretation of scripture.
This is an important backdrop when reading the rest of this answer.
There are several clues directly in Genesis that the creation account is not meant to be taken literally. Some good examples:
"Morning" and "evening" pass before the sun is created. Either the sun literally existed before it was described in Genesis, or there were no literal days until the sun was created. See this question. A third hypothesis is that the early days of creation meant "24 hour periods," and not specifically "days" as we know them now. But then why refer to "evening" and "morning"? Either the word "day" is metaphor, or "evening" and "morning" are metaphor. In any case, this aspect of the creation account cannot be taken completely literally.
At minimum one of the key words ("sun", "day", and/or "morning/evening") cannot have the same literal meaning it has today.
The seventh day never ended. This seems to be an indication that the days are metaphorical, and that we are presently living in the seventh "day." At the very least, it indicates that the 7th day was somehow distinct and special from the 6 others.
The Genesis 2 account of creation doesn't precisely agree with the Genesis 1 account of creation, in terms of order of creation. Man appears to be created before plants, then later placed in "the garden."
Genesis 2 describes a number of events that happened between the creation of Adam and the creation of Eve:
- God planted a garden in Eden
- Adam worked in and cared for the garden
- Adam named all of the animals
Working and caring for a garden is clearly not a one-day task. Nor is naming all of the animals, nor discovering, in this process, that none of the animals are suitable helpers for Adam.
I discussed some of this in this answer, but will elaborate further here.
The Hebrew word for day (Yom) used in Genesis 1 has many meanings: (a) Some portion of the daylight (hours), (b) Sunrise to sunset, (c) Sunset to sunset, (d) A segment of time without any reference to solar days (from weeks to a year to several years to an age or epoch) [i.e. "In my grandfather's day" or "in the day of the dinosaurs]
YECs have several arguments for why Yom in this context means 24-hour day, but they all fall short. I'll discuss two here:
Claim: The phrase "evening and morning" "is used 38 times in the Old testament, not counting Genesis 1. Each time, without exception, the phrase refers to a normal 24-hour-type day."3
Interestingly, the word "day" (or yom) appears in none of these examples. The word's plural form occurs only in 1 Samuel 7:16. In only a few of the 38 examples do the words "evening" and "morning" appear in the same sentence or verse. The phrase "evening and morning" appears only one time, in Psalm 55:17. David said, "Evening, and morning, and at noon, will I pray" (KJV). However, even this occurrence is of little relevance. The expression being considered--"and there was evening, and there was morning"--appears only in Genesis 1.2
Claim: 358 out of 359 times Yom is used in the Bible, outside of Genesis 1 and with an ordinal modifier, it represents a 24-hour day.1
Only 249 of these uses use the singular form of 'Yom', and all 249 are in the context of human activity.2 Genesis 1 is clearly referring to divine activity.
"Morning to morning" or "evening to evening" are common ways of denoting days in Hebrew, however the phrasing "and was evening, and was morning" is unique to Genesis 1, which seems to indicate that these days were unique in some special way.3
Historically, the church has had a very non-dogmatic view on this issue. Most recorded commentary on this issue has approached the matter mostly as a matter of idle musings, and of little or no real spiritual significance.
The portion of Genesis 1 that describes the six creation days receives more commentary from early church scholars than does any other text in the Bible. However, of the approximately 2,000 pages they wrote (a commentary called the Hexameron), only about two pages address the duration of the creation days. Clearly, the early church fathers did not consider the length of these days a major doctrinal point.5
Historically, Jewish and Christian scholars have not considered the creation account to mean a 6 literal day creation. The earliest scholars to even address the issue (around 13 B.C) believed that God instantaneously created everything, and that the 6 days were purely figurative of order and completeness.5
St. Augustine spoke the most strongly on the matter, saying: "As for these 'days,' it is difficult, perhaps impossible to think--let alone explain in words--what they mean."6 and "But at least we know that it [the Genesis creation day] is different from the ordinary day with which we are familiar."7
There is a plethora of scientific evidence that suggests the world appears to be much older than YECs claim. Although YECs naturally dispute much of this evidence as weak science, but many of these claims require distorting science. I openly admit that science does not have all the answers about the creation of the world yet, and never will. However, that does not change that many of the scientific principles used to date the earth and/or the universe are very hard to dispute.
You specifically asked not for scientific evidence in support of the OEC view, so I won't go into any detail here. That would be well beyond the scope of this site anyway. I'll only mention one example briefly, and further reiterate my point made above about the Character of God--that God does not lie, and that creation reveals Him. Therefore, whatever good science says about the Universe must, IMO, be true, as a true reflection of God through his creation.
The one example I want to mention, is the simple deductive reasoning that gives astronomers an approximate age for the universe of somewhere around 14 billion years. Read the full details here, but the nutshell version is that by using red/blue-shifting, we are able to observe how quickly the universe is expanding. By doing some backwards math, we can calculate that the universe was all at a single point ~14 billion years ago.
I've heard some YECs argue against this by suggesting that the speed of light must have traveled faster in the past, giving the universe the appearance of greater age (due to greater distance between galaxies). However, if the speed of light was not constant, the formation of our life-sustaining sun would not be possible. As the 'c' in E=mc2 stands for the speed of light, if that changes, then either the E (energy) or m (mass), or both, must also change accordingly. If this theory was right then "either Adam and Eve would have been incinerated by the Sun's trillionfold increase in heat or the elements essential for building their human bodies would not exist."8
Another theory is that light travels faster (or takes a short cut) over vast distances in space. This theory came out before much work on Einstein's theory of general relativity, which has since proven this theory implausible.9
Believing in an old earth does not at all detract from the authority one believes the Bible holds. It's not a matter of believing that the bible is "wrong"--it's a matter of believing that that prose ought to be interpreted as prose, and that scientific literature ought to be interpreted as scientific literature--and swapping those in either direction detracts from a proper understanding of the thoughts the author intended to communicate.
Interpreting anything too literally is NOT doing it a service, no matter how pure the intentions of the interpretor.
Now, from a scientific perspective, I think it's easy to forgive the early church scholars for interpreting the Genesis creation account without any (meaningful--from a modern perspective) scientific perspective. However, if the YEC position held any weight in terms of literature or hermeneutics, surely these scholars would have picked up on that.
To believe either of the overarching views, a few "concessions" must be made:
To believe in an Old-Earth:
- The Genesis creation account is metaphorical, and not written as a scientific text.
- The flood account is told from the perspective of those writing it, for whom the entire known earth did flood, but not necessarily the entire literal earth.
To believe in a Young-Earth:
- God arbitrarily chooses use words that have practically no meaning ("day," "morning," and "evening" prior to the sun existing)
- God gave Adam super-human powers, or made the 6th day extremely long, or performed some other miracle to allow Adam to name all of the animals in a single day.
- God created the earth with the appearance of age
- God teleported animals to and from the Ark from/to multiple continents
- Well established scientific principles are flatly wrong, despite independent verification by many people (both religions and non-religious) over many years, in some cases over centuries.
- Reconcile personally that these apparent contradictions don't make God a liar
To me, the first set of "concessions" is much easier to make. It only asks me to read literature in the context it was written. It doesn't ask me to believe what would appear, to an external observer, to be a bunch of fairy tales.
As a final note, an observation that doesn't necessarily add any weight to the OEC position--so I mention it here, and not in my main arguments:
OEC is much less of a stumbling block for most non-Christians, because it doesn't require them to make what can easily be considered an "absurd" leap of faith, to believe that science is flatly wrong, etc. In the words of Dr. Joshua Zorn:
The worst aspect of YECS teaching is that it creates a nearly insurmountable barrier between the educated world and the church.4
1Mark Van Bebber and Paul S. Taylor, Creation and Time: A Report on the Progressive Creationist Book by Hugh Ross p. 73
2Hugh Ross, A Matter of Days, p. 74
3Ross, p. 76
4Dr. Joshua Zorn, The Testimony of a Formerly Young Earth Missionary
5Ross, p. 42
6Aurelius Augustinus, The City of God, Book XI, Chapter 6, 14:196
7Aurelius Augustinus, The Literal Meaning of Genesis, Book Five, Chapter 2, as translated and anotated by John Hammond Taylor, vol. 1, books 1-6 p. 148
8Ross, p. 165
9Ross, p. 166