Did God create the earth in 6 literal, 24 hour days or did each of those "days" consist of hundreds, thousands, millions, or even billions of years?
I believe (and as a church we believe) that God created the earth in 6 literal, 24 hour days.
Why do I (we) believe that?
"Since God's revealed Word describes this Creation as taking place in six 'days' and since there apparently is no contextual basis for understanding these days in any sort of symbolic sense, it is an act of both faith and reason to accept them, literally, as real days." - Whitcomb and Morris, "The Genesis Flood"
The Biblical text supports 6 literal, 24 hour days.
(1) The Hebrew word that is used for day always (in the writings of Moses) refers to a literal, 24 hour day when it is used with a number such as you have in Genesis chapter 1.
(2) 6 times in Genesis chapter 1, after each day of creation, God records for us this phrase:
"...and the evening and the morning were the _____ day."
This phrase supports the understanding that "day" in Genesis chapter 1 meant a literal, 24 hour period of time.
God did not record, "...and thousands of years were the _____ day."
God did not record, "...and millions of years were the _____ day."
God dod not record, "...and billions of years were the _____ day."
Throughout Scripture, the words evening and morning are each used some 100 times. And, each time they are used they mean nothing other than a literal evening and morning of a literal 24 hour day.
(3) In Exodus 20:9-11 and Exodus 31:15, God uses the six days of creation as a reference for His command to the children of Israel that they were to work six days and then to rest on the seventh day. Why would God do this if the six days of creation were not 6, literal days?
Not only does the Biblical text support the teaching that the days of Creation were 6, literal days but...
Common sense supports the teaching that the days of Creation were 6 literal, 24 hour days.
In Genesis 1:3, we are told, "And God said, Let there be light: and there was light." How much time did He need? The plain reading of that verse teaches that it was instantaneous; as soon as God spoke those words, the light appeared.
I have often heard and said myself, "When the plain sense makes common sense seek no other sense lest it leads to nonsense!"