Day (H3117) in Genesis 1-2, is defined one of two ways: 1) a literal day; 2) figuratively (a space of time defined by an associated term). If you reject the literal day definition, the associated terms to the same word, day (H3117), given in Gen 1:5, 8, 13, 19, 23, 31 are evening (H6153), which means dusk, and morning (H1242), which means dawn and/or morning, confirm without doubt the days of creation are literal. God used both meanings of Day (H3117) in Gen. 1.
There is no room for metaphoric interpretation in Gen. 1-2. Metaphor means a figure of speech in which a word or phrase is applied to an object or action to which it is not literally applicable. The terms in Gen. 1-2 are literally acceptable.
To teach and/or hold any other view is an attack on the foundation of the Bible, which in turn, is an attack on Christianity itself, as well as the Author of Scripture. God's repetitive use of evening and morning provide the needed clarity within the text regardless of what outside sources, Christian or otherwise, may say. The Bible is the only source of inerrant truth. If the Bible does not say what it means, it means nothing and we cannot trust the Scripture, it's that simple. Stop means stop, not move slowly. Likewise evening and morning mean evening and morning.
If one can believe Christ raised from dead (mandatory for salvation), one can believe the virgin birth and likewise easily believe God created the world in six literal days and Jesus is the only way of salvation. Why do we believe any of it? Because the Bible says it, We believe it! Luke 1:37 "(37) For with God nothing shall be impossible."
The real question is not if the days were millions of years, a heretical teaching, rather why did God take so long (six literal days) to create the world? God provided an answer for us: Exod 20:11 "(11) For in six days the LORD made heaven and earth, the sea, and all that in them is, and rested the seventh day: wherefore the LORD blessed the sabbath day, and hallowed it." Again, day is to be understood according to the terms associated with it. The number six means six.
The only reason one would question the literal days is if one wants to merge creation with evolution. This is not possible on many levels, a few are listed:
1) God created every kind after its own kind, which DNA proves true while evolution believes a kind can become another kind over time; A zygote is always synthesized from the union of two gametes, and constitutes the first stage in a unique organism's development. Zygotes are usually produced by a fertilization event between two haploid cells—an ovum (female gamete) and a sperm cell (male gamete)—which combine to form the single diploid cell. Such zygotes contain DNA derived from both parents, and this provides all the genetic information necessary to form a new individual.
2) Gen 2:7 "And the LORD God formed man of the dust of the ground, and breathed into his nostrils the breath of life; and man became a living soul." This is contrary to evoltion which states humans came from lower life forms.
3) Death, spiritual and physical, started once sin started, for the wages of sin is death. (Gen. 2:17; Rom. 6:23), therefore there cannot be death prior to adam's sin. Evolution needs millions of years of death to “generate” life.
4) Darwin, in is own words, wanted evolution to be true because he rejected God. These views are opposing and cannot be merged.
If you wish to do further study on a young earth goto www.icr.org and http://www.answersingenesis.org/. Christian scientists committed to the literal interpretation of the Genesis because they understand without it the whole of Scripture falls apart. If we cannot trust God to tell us the truth regarding the beginning, there is no reason to believe the rest. To accept the heresy that Genesis is metaphoric, you are inadvertently doing the following: changing the meaning of metaphoric, denying the twofold definition of day (H3117), denying the actual meaning of both evening and morning, denying the meaning of the word six in Exod 20:11 "For in six days the LORD made heaven and earth, the sea, and all that in them is, and rested the seventh day: wherefore the LORD blessed the sabbath day, and hallowed it.", denying the inspiration of the Word of God (2 Tim 3:16, "All scripture is given by inspiration of God, and is profitable for doctrine, for reproof, for correction, for instruction in righteousness:" AND 2 Pet 1:21 "For the prophecy came not in old time by the will of man: but holy men of God spoke as they were moved by the Holy Spirit."), attempting to merge both evolution and creation and attacking the foundation of Word of God as the only source of inerrant truth by by rejecting the clear historical account (evidenced by context).
Lastly, if you cannot accept the Bible as divinely written, inerrant and literally true regarding Genesis and the rest of it, when not clearly figurative and yielding to the meaning of figurative, you have no place teaching inside the House of God, regardless of denomination. The principle of this verse is true in this discussion: Rom 3:4a "God forbid: yea, let God be true, but every man a liar;" It really does not matter if you are comfortable with what you teach, the question is, is God? Would God approve of you calling Him a liar. Context is clear, there was evening and morning the first day. This phase is repeated six times replacing only the day's number. We cannot take what is clearly not figurative and make it figurative or we destroy the meaning of figurative and open the Bible to mean anything, including the idea that salvation is figurative and Jesus being the only way to salvation as being figurative.