Isaiah 38:8 was used to prove that the Bible “literally” said the sun revolved around the earth. We believe that the shadow of the sun went back 10 steps, but can now understand that the truth is that the earth revolves on its axis and also revolves around the sun.
In the same way, we understand that the four corners of the earth in Revelations 7 is not literal and that it was possible in Genesis to have an evening and a morning before there was a moon or sun.
All scripture is given by inspiration of God, and is profitable for doctrine, for reproof, for correction, for instruction in righteousness (2 Timothy 3:16)
Just because fallen man, apart from the guidance of the Holy Spirit, is incapable of understanding the things of God and the Word of God, does not negate the fact that the Scriptures were written by God and are infallible and absolutely true.
There have been many, many instances through the thousands of years since the Scriptures were completed that they have been twisted, misunderstood in the light of the limitations of the time in which they were read and understood to mean something quite different years later when science and technology made advances, denied in light of the fact that prophecies which have been fulfilled were, in years past, seen as nonsensical and impossible by people living in a time before events occurred that brought those prophecies to pass.
The fact that man cannot fathom the thoughts and words of God without the help of God and the revealing of the Holy Spirit to man of what Scripture means, does not mean that the Bible "is not literally true". God has also said:
18 For the message of the cross is foolishness to those who are perishing, but to us who are being saved it is the power of God. (1 Corinthians 1:18)
You have to know God personally to understand His Word. If somebody claims that the Bible is "not literally true", then they are revealing something about themselves.
The theory of evolution says there is no such thing as design in nature. How do you rationalize that as being compatible with Christianity? A non-literal interpretation of the Bible is not much help on this point.