The Gospel of Thomas: The “fifth Gospel” or a writing that excludes itself from the canon?

Summary: I. What is a Gospel? II. How many Gospels? III. Characteristics of the
Gospels. IV. Does the ‘GTh’ qualify as a Gospel? V. Conclusion.

In the first centuries of Christianity many writings appeared bearing the title
“Gospel” yet only four of them ended up being recognized as such and as worthy
of being read, copied, revered and transmitted through the ages until our day.
The rest were considered spurious and most ended up being lost to posterity.
Thanks to the new-found interest in archeology in the 19th and 20th centuries,
many of them have been found and made available for scholarly study. One of
these—the Gospel of Thomas—has received a great deal of interest mainly due to
its similarity both in its form to the hypothetical document “Q” of the two source
theory behind the formation of the synoptic Gospels, as well as in some of its
contents to some of the sayings of the Lord found in the canonical Gospels. That
of course raises the question: why was the Gospel of Thomas not included among
the canonical Gospels? In this paper, we will examine the concept of “Gospel”
in a bid to elucidate what it is that was found to be common to the 4 canonical
Gospels and yet lacking in the Gospel of Thomas, so much so that, despite the
similarities with the other four, it ended up being altogether rejected.