Human beings using human language were made fit by God to give us His Word (2 Tim. 3:16–17; 2 Peter 1:16–21). Consequently, His Word—the Old and New Testaments—is entirely free of error and, in fact, is incapable of error (John 17:17; Titus 1:2). That argument appears sound, given what we know about the Lord's nature, does it not? Yet some evangelicals have continued to deny the inerrancy and infallibility of Scripture. Interestingly, many of them claim to do so based on theological grounds.
The historic Christian understanding of the person of Christ is that He is one person who possesses two natures: a divine nature and a human nature. Each nature retains its unique properties, and the two natures remain distinct, though inseparably united in Christ's person. Thus, according to His divine nature, as the second person of the Trinity, the Son of God is omniscient, omnipotent, and so forth. According to His human nature, the incarnate Christ needs to eat food to survive, grows in knowledge, and so forth.
Using the hypostatic union as their rationale, some thinkers have taught that Christ could—and did—err. So, we cannot affirm Scripture's inerrancy and infallibility, for some of the words of Jesus might be in error, and we find His words only in the New Testament. These thinkers reason based on a particular understanding of what it means to be human. If "to err is human," and Jesus is truly human, the thinking goes, then Jesus must have erred because making errors is inherent to humanity. Some have even extended this to argue that all of Scripture may contain errors. Since the Bible is a divine-human product, it must contain errors because human beings necessarily err.
Ultimately, these views reflect a poor understanding of what it means to be human and of what makes an error an error. We do see Jesus at times display human limitations, such as His not knowing the identity of the woman who touched His clothing in hope of being healed (Luke 8:45–46). Lacking such knowledge, however, is not an error; it merely reflects that Jesus was not omniscient in His humanity. One can lack knowledge and still tell the truth. Further, as we have seen in other studies, that human beings can err does not mean that they necessarily err. People earn perfect grades, at least at times, while remaining fully human. Believing Scripture is inerrant and infallible, therefore, is not a denial of the humanity of our Lord or of the Bible's human characteristics.
In the interest of "protecting" the humanity of Christ, many people want to believe that He held some incorrect views or taught some wrong things. But if Christ did teach or believe error, that denies His full deity, for God only speaks the truth. It is important to be well-grounded in our understanding of Christ so that we can rightly affirm both His full humanity and full deity. If He is not both truly man and truly God, He cannot save us from our sin.