This is a common question people often ask but the mere presence of errors does not render the Bible useless for faith or make it untrustworthy. Behind this question usually lies an all or nothing view of Scripture that is not well thought out. Does the presence of an error in one of my physics textbooks render it all suspect or useless? Of course not. What about five inconsequential errors? The answer is the same. I recently read Matthew Kelly's 'The Biggest Lie in the History of Christianity' and he mistakenly referred to butterflies as emerging from a cocoon instead of a chrysalis--a mistake I have also made. Does this terminology snafu render everything else in the book suspect or useless? Absolutely not! Mere errors in the Bible do not necessarily undermine its trustworthiness. Now if a physics textbook is observed to start making a significant number of errors when it came to actual physics content, since composing such information is its central purpose, one would rightfully be skeptical of the remaining text. If the Bible starts getting a bunch of things completely wrong about God and salvation when properly interpreted, then we would have cause for alarm.
This question appears forceful upon first hearing it but it doesn't amount to very much once its unraveled. Where in life do we have inerrant sources? What book, magazine, historical document, doctor, mechanic, school teacher, pastor or church is inerrant? We use imperfect sources all the time and are quite adept at doing so. A work does not need to be inerrant to be useful. It just needs to be reliable for its intended purpose. We can say the same thing about eyewitness testimony. It is painfully obvious to experts today that eyewitnesses make all sorts of mistakes. This does not render all eyewitness testimony useless. It simply has to be used judiciously. The question is apparently setting up a double standard. In responding to the "all or nothing" charge, Paul J. Achtemeier wrote that ". . . people do not operate in other areas of life on the principle that one mistake or error renders all other statements or acts coming from that source totally untrustworthy. One's trust in a friend is not irrevocably shattered if one finds that in some matter of historical information that friend should prove to be in error. Life has a way of continuing to function, even in the absence of absolute certainty, and whatever else the Bible may concern, it is surely about life." [The Inspiration of Scripture, pp. 36-67]
The Bible was not written to be a scientific text nor is it a strict historical biography in the modern sense. Its purpose is to preach the good news so that we might be saved by it. Its purpose is mediating the sacred and bringing salvation to people. Its record speaks for itself in that regard so we can deem the Bible reliable and useful for its intended purpose by God, whether inerrant or not. Historical, scientific or normal human errors do not impugn upon its efficacy at achieving this purpose. In order for the Bible to be considered useful and inspired it must only serve the purpose for which God intended it. The purpose of the Bible is not to teach us exactly how Judas died or how long it took God to fashion the earth or whether or not Abiathar or Ahimelech was high priest when David ate the showbread. The purpose is to mediate the sacred and bring people to God through the redemptive work of Jesus. God and the Holy Spirit can work through a text with errors. It would be obnoxiously belittling to God to suggest otherwise. The Old Testament provides a good model in that God was able to accomplish His will through sinners over and over again. The Patriarchs and Israel constanty screwed up, just as we do today, but God's will was still accomplished. We should not short-change God's abilities or underestimate Him. If life were a game of chess He would be a grandmaster and we would all be novices. No matter what moves we make, eventually he will win.
2 Timothy 3:15-17 speaks to the purpose of scripture: "and how from childhood you have known the sacred writings that are able to instruct you for salvation through faith in Christ Jesus. 16 All scripture is inspired by God and is useful for teaching, for reproof, for correction, and for training in righteousness, 17 so that everyone who belongs to God may be proficient, equipped for every good work." NRSV
The most important part of this passage to me is that God left us a record and message of salvation history so that we
could come to know him through his Son. Scripture instructs us for salvation through faith in Christ Jesus, teaches us and trains us in righteoussness so that we may be equipped to do good works through faith. I am certain that a text does not need to be factually inerrant for God to use it to lead us to Jesus, to be useful for teaching, reproof, etc. Can a person not write an informative work that has errors in it while the central message remains true? Whether or not the Bible is inerrant, its salvific track-record delineates its general trustworthiness in fulfilling God's intended purposes. It is not the Bible that saves us but God working through the Bible who saves. The presence of errors in the Bible might justifiably open up a host of other questions, but it does not undermine it's trustworthiness which is well established by its salvific track record.