There are two things that must be said in challenge to literalism. One, if you believe every word of the Bible is true, then you are obligated to rethink certain issues in light of biblical evidence. For example, salvation, in light of evidence that reveals the original Greek language of the NT does not teach the doctrine of everlasting damnation but rather teaches what some call "Christian Universalism," and the fact that many if not most of the early church fathers also held this view. This is part of the historical record for anyone to see if they look carefully enough.
There are of course many other issues as well that demand attention because of misreadings stemming from the literalist community's practice of lazy biblical interpretation that is not true to the original language and culture of the Bible, e.g. the need to rethink the church, homosexuality, the end times, etc. If one believes the whole Bible is true then make it the original words and historical context that you believe, not later traditions, mistranslations, or misinterpretations. Be sure your Bible belief is on a firm foundation.
The second challenge is that a literalist viewpoint is tantamount to worshiping the Bible, not God. The Bible never claims we should view it the way literalists do. It never claims to be inerrant and the early church never used the NT as such. Literalists go beyond the original intent of Jesus, Paul, and the earliest church. If you believe the Bible is all true, you must go beyond the pat answers and proof texts and go straight to the original language and historical setting when addressing contentious issues. If this is not done, it's using the Bible irresponsibly.
If in the course of this examination it becomes evident that the Bible is not all 100% factually true, the question is, Then what in the Bible can we trust? It must be hit home that there's plenty to trust in a fallible Bible, written by humans who claim to have encountered God, just as there's plenty to trust in any fallible historical manuscript. Just as historians use tools of historical evidence, authenticity, archeology, logic, etc., people of faith can use their minds, spiritual discernment, common sense, and historical & biblical evidence to ascertain what's trustworthy in the Bible. We won't all agree on details and some things will remain a mystery, but there are many things we are bound to agree on. For example, the love ethic of Christ, the new way of relating to God and humankind through the lens of love not the written code, that runs as a powerful theme throughout the NT. A theme that says Love for neighbor, not religious affiliation or believing the exact right doctrines, fulfills what God desires.
What can one trust in the scriptures? We trust the overall themes, the conclusions, the overall message of the Jesus Movement (as portrayed in the NT and other historical commentary), not assigning equal absolute authority and certainty to every individual word, verse, or passage. We draw out a message from the pattern and conclusions the biblical/historical record comes to (the Gospels, Pauls' letters, and historical evidence that reinforces the NT or highlights reasons to suspect parts of it). That kind of trust in holy writings is a more genuine faith. It respects the mystery of God's revelation and calls for a responsible use of a set of historical writings from which we can learn an inspired message, rather than insisting on a strict, adherence to an "infallible" text, or else. The former leads to unity, not uniformity, as readers major on what really counts: love, trust, and hope. The latter leads to division, as readers focus on whose interpretation is the absolute correct and infallible one and judge others who disagree.