To begin with, I have to admit that it can seem pretty subjective when it comes to deciding what Jesus said by looking at the scriptures and applying the tools of criticism (methods of determining the authenticity of sayings, events, and authorship). And yet, the tools scholars have available are time tested and honored.
So, what are the tools scholars use to decide what Jesus actually said?
The first tool is vocabulary. If Ashleigh’s father wrote a paper for her, her teacher would know she hadn’t written it because her dad would use words Ashleigh wouldn’t use. When scholars are looking at the biblical writer’s words, they have the opportunity to list and to examine the vocabulary used. If there is a particular section where the vocabulary significantly changes, we can assume someone has added their own words sometime in the past. A good example is Mark chapter 16. In most Bibles today, Mark 16 ends at verse 8. However, it used to end at verse 20. One reason for this is that scholars compared the vocabulary to the rest of the gospel. At that point it became apparent that Mark didn’t write 9-20 because there was a distinctive vocabulary shift and there were many words there that Mark did not use elsewhere.
A second tool scholars use is grammar. When looking at a particular work, it is pretty clear when grammatical constructions shift. In virtually every language there are formal forms of the language as well as informal forms. When Matthew quotes the Old Testament, as he often does, his grammar is more stilted than when he is in the midst of a parable or recounting an event. Further, John’s writings tend to be more formal than Paul’s writings, and Paul’s more formal than Mark. Indeed, this is one reason some scholar’s dismiss John’s authorship of the book of the Revelation—the grammatical constructions are dissimilar enough to warrant doubts.
A third tool is content. Here is where Ashleigh’s question finds an answer. The content of a single writer, or a single speaker, tends to be fairly consistent and very often follows particular themes. For instance, if we were to read a collection of Gandhi’s sayings and we came across the words, “And I say to you, whenever the authorities are blind to the plight of the poor, we must rise up and strike the oppressors down” we would seriously question the authenticity of the so-called “quote.” The same is true of the scriptures. Indeed, this is the basis of the Jesus Seminar that was (is) so controversial in the 1990s.
Ashleigh’s original question specifically asked how I “knew” Thomas 85 was not genuinely something Jesus said. Of course, the answer is that I don’t know; however, in my opinion, as well as in the opinion of most scholars, it is highly unlikely he said the words Thomas cites: “Jesus said, ‘Adam came from great power and great wealth, but he was not worthy of you. For had he been worthy, [he would] not [have tasted] death.’”
There are a couple of clues as to why this would be considered an inauthentic saying of Jesus. For one, there are no parallels passages in any of the other gospels. This is one way in which authentic sayings of Jesus, or anyone else for that matter, are authenticated. If several sources include the quote, then it’s more likely the words, or at least something akin to the thought, was actually spoken. However, nothing like this passage is found in any other gospel.
Secondly, the adamic theme is unique to Thomas. Nowhere in the gospels do we see Jesus mentioning Adam. Indeed, the only time the word “Adam” is found in the other gospels is in the genealogy of Luke 3.
And finally, there is the worthiness vs. eternal life issue. Although the New Testament gospels contain the phrase, “will not taste death,” it is in the context of the coming of the Kingdom of God (Matthew 16.28, Mark 9.1, Luke 9.27). Thomas 85 suggests that had Adam been worthy enough he would not have died. This is not at all similar to Jesus saying that some will live until the Kingdom comes—especially if one associates the Kingdom with Jesus’ death and resurrection. And so, because the theme “never-ending life in association with worthiness” is unknown anywhere else, it is unlikely an authentic saying of Jesus.
Any one of these three reasons on it’s own
may not be enough to reject a saying of Jesus (or
anyone else, for that matter). But all three
together makes for a rather compelling case against
this passage in Thomas.