The modern habit of reinterpreting the days of creation as other than real days didn’t happen because of the Bible. The vast majority of Christians believed in literal days until approximately 250 years ago when deep-time concepts began to be popularized, and the story of evolution was promoted behind it as so-called science. Fearing to be thought of as unintellectual and unscientific, theologians at that time began to compromise the Word of God, even though they admitted it didn’t appear to be the plain reading of Genesis 1 in context. This has continued from way back then to this day. And although it’s not a salvific issue, it is indirectly a gospel issue (i.e., it can affect people’s trust in the gospel). Because it has to do with biblical authority. As most people have come to believe that if you can’t take the Bible as plainly written in one area, why should you believe it in any other?