It has become a common phrase of many Bible-bearing Christians—perhaps more of the fundamentalist variety—to point to a particular passage in Genesis, and use other passages in the Bible to then essentially make sense of it. While this has been done in a variety of circumstances, I just want to focus on one particular point of Genesis: the six days of creation from Gen. 1.
An earlier post mentioned the jarring error in Genesis: that God tells adam if he eats from the Tree of Knowledge, he’ll die the same day—but once adam does that, he manages to hang on for another 930 years.
But this isn’t the only problem with time in Genesis—he six days of creation, in fact, presented another problem. Even to ancient interpreters of the Pentateuch, the order of creation presented some problems: as Ryan mentioned earlier, the son, moon and stars were all created on the fourth day—but days are defined by the movements of those bodies, so how could there have possibly been days before the sun and moon and stars were created?
Hence many ancient readers/interpreters sat there, said the ancient equivalent of WTF?, and then came up with an idea to solve the Genesis / adam problem. What if a day to God were really a thousand years? Hence a famous Psalm: “For a thousand years in Your [God’s] sight are as yesterday, the way it passes, or like a watch in the night” (Ps. 90:4). Following this lead, other ancient writers put similar passages in a variety of other scriputural or apochyrphal works: Letters of Peter, Letters of Barnabas, Jubilees, and others (See Kugel, “How to Read the Bible, 50). This solved two problems: it made God’s promise that adam would die in a day work out (since a “day” was really a thousand years, and adam lived less than a thousand years) as well as the order of creation (“day” is not an actual day, so it doesn’t matter if the sun/moon/stars were not created until later).
The important part to recognize is the day = thousand years is a much later addition to the text of Genesis—nowhere in Genesis itself is it at all clear that one day to God equals a thousand years; this was merely the result of problems within the text. And this new equation was their solution. Thus, it should be taken with a grain of salt.