While incarnation and inspiration are not univocal divine acts, the analogous relationship between them should lead us to have more confidence in the complete truthfulness of Holy Scripture, not less.
In other words, for Scripture to be “fully human” doesn’t mean that the human authors necessarily made mistakes any more than for Christ to be “fully human” means that he necessarily sinned.
The dual authorship of Scripture and the dual natures of Christ actually push us toward affirming the opposite - because Scripture is authored not just by human beings but ultimately by God, it is without error, just as Christ as God-in-flesh is necessarily without sin.
To put it simply - the Bible is inerrant for the same reasons that Jesus is sinless.
It is a historical and theological caricature to say that inerrancy is simply an invention of modernist fundamentalism. While the term may not have been used prior to modernity, the concept of the Bible’s complete truthfulness is found throughout church history.
More importantly, affirmation of inerrancy is rooted in God’s own testimony to the purity of his word in scripture, which is of course ultimately grounded in the doctrine of God. Affirmation of inerrancy is a corollary affirmation to theology proper, Christology, & pneumatology.
