My friend Guy Davies sent me this excellent quote from Kevin Vanhoozer on inerrancy:
The basis for the doctrine of biblical inerrancy is located both in the nature of God and in the Bible's teaching about itself. First, if God is perfect – all knowing, all wise, all-good – it follows that God speaks the truth. God does not tell lies; God is not ignorant. God's Word is thus free from all error arising either from conscious deceit or unconscious ignorance.
Such is the unanimous confession of the Psalmist, the prophets, the Lord Jesus and the apostles. Second, the Bible presents itself as the Word of God written. Thus, in addition to its humanity (which is never denied), the Bible also enjoys the privileges and prerogatives of its status as God's Word. God's Word is thus wholly reliable, a trustworthy guide to reality, a light unto our path.