A common saying of Jesus Christ that inerrantists use to support inerrancy is found within Matthew 5:17-18. According to this text Christ says the following:
“Do not imagine that I have come to do away with the law or the prophets. I have come not to do away with them, but to fulfil them. I meant it when I say that, until heaven and earth disappear, not one letter, not even one stroke of a letter, will disappear from the law, until everything is accomplished.”
Three things might be said in response to the inerrantist’s use of this text. On a first note, the reasoning behind the inerrantist’s use of it is circular. In other words, the only reason they are able to claim that these verses represent “Jesus’s teaching” on scripture’s inerrancy is because they already presuppose that the Gospel of Matthew is giving an inerrant record of Jesus’ words. In other words, inerrancy is supported by the assumption of inerrancy.
But there is good reason to doubt that Jesus actually said these words found in this verse of Matthew. It seems that what Jesus says here regarding the law is done to support Matthew’s own theological agenda. What agenda? By the time Matthew’s gospel was written there had already been mass conversions of gentiles to early Christian-Judaism. The policy of Paul and others was that the laws of Moses did not apply to the gentiles, a policy that was highly controversial to 1st century Christians. Many Jewish Christians dissented from Paul’s position, arguing that the law of Moses was still applicable, and Matthew’s gospel seems to take that position in opposition to Paul and other gentile churches.
Jesus also says that “until heaven and earth disappear, not one letter, not even a stroke of a letter, will disappear from the law.”
The phrase “until heaven and earth disappear,” is a Hebrew idiom that means “until forever.” In other words, in Matthew, Jesus says that the laws of Moses will never become irrelevant, and there will never be a time when it should not be obeyed. On the other hand, Luke’s author quotes this same saying of Jesus with a subtle yet significant variation in wording: “But it is easier for heaven and earth to disappear than for a single stroke of a letter in the law to be cut out” (Luke 16:17).
Note, however, that in Luke, this saying is preceded by a rather different claim: “Until John came, the law and the prophet were in effect; since that time, the good news of the kingdom of God is proclaimed, and everyone is rushing madly to get into it” (16:16).
In Luke’s gospel, the same saying of Jesus is given the opposite meaning to that of Matthew. In Luke, although it is difficult for the law to pass away, it has. It was only valid until the ministry of John the Baptist after which it was set aside in order to allow the gentiles to come into the kingdom. This also happens to be Luke’s theological agenda, being a gentile himself. Thus, the Gospel of Luke takes Paul’s side in the controversy, and the Gospel of Matthew takes the side of the Jewish Christians who are highly polemicized in Paul’s letters as “Judaizers.” Both Luke and Matthew use the same saying of Jesus to articulate polar opposite positions.
Furthermore, even if this saying is original to Jesus, and conceding that by it he meant that the law and the prophets were inerrant (and claim he does not make), Jesus still makes no statement about the other writings, namely the books of the Hebrew scripture that fall outside of the categories of the Law and the Prophets.