“In the beginning, God created the heavens and the earth.” — Genesis 1:1
One thing that young-Earth creationists and the New Atheists agree on is that if one were to believe the Bible, one would have to believe that the universe, including planet Earth, is only 6000 years old. Of course, both the YECs and the atheists are wrong.
Genesis 1:3 through 2:3 is divided into seven days; six days of creative activity, and the seventh day, which is God’s Sabbath. For days one through six, there is a pattern of “And God said, __________” for the beginning of the day, and “And there was evening and there was morning, the nth day” for the end of the day. Genesis 1:1-2 lies outside of this pattern, and so is likely not intended to be considered part of the first day of creation:
In the beginning, God created the heavens and the earth. The earth was without form and void, and darkness was over the face of the deep. And the Spirit of God was hovering over the face of the waters. — Genesis 1:1-2 (ESV)
Because the first two verses are outside of the “days” structure, the “heavens and the earth” are, according to the text, of indeterminate age. “In the beginning” could have occurred immediately before the six days (as YECs believe), 13.5 billion years earlier, or some other amount of time. The Bible does not say.
There is much more to the Biblical case for an old Earth (or better, the Biblical case for Biblical ambiguity regarding the age of the Earth), just as there is much more to the YEC case for a young Earth. But I think it is extremely important to point out that the starting point of the creation passage in Genesis is not “Earth is young” but ambiguity regarding the antiquity of the creation.
Grace and Peace