A similar discussion on this same question can be found at Stand to Reason’s site here. In his article, Koukl concludes that no, Scripture is not sufficient – for every problem or issue. The Bible is sufficient for leading people to salvation and to the good works of sanctification (2 Timothy 3:15,17), but it was never intended be the only beneficial or adequate source on human existence. Many Christians, the author argues, while well intending, actually “deny believers a source of wisdom and knowledge the Bible itself encourages us to consider.
I must say that I agree with Mr. Koukl on this matter. It seems like the best question to ask in response to the question “Is the Bible sufficient to help someone” is, “sufficient in what way?” In Scripture we see a continuum of reconciliation – mankind falls from perfect relationship with God, and slowly throughout the pages of the Old Testament and New Testament, humanity is reunited with God through the person of Jesus Christ. So, the Bible’s goal is to lead people into right relationship with the Triune God. And this it sufficiently. However, Scripture is not necessarily sufficient for all issues (though it does indirectly and often directly address many human problems). While I do not want to depreciate the authority of God's Word, we should be careful of zealously trying to make Scripture say more than it intends.