Why is the Gospel of Thomas not in the Bible?

Answer 1

Answer
The Gospel of Thomas was written in a different branch of Christianity than the branch that gradually came to dominate and which selected its own New Testament canon. Nevertheless, the Gospel of Thomas was very popular in the proto-Catholic-Orthodox Church and there was pressure for its inclusion.

Ireneus, bishop of Lyons, had the last say, deciding that it was as natual for there there to be four gospels as for there to be four corners of the earth, and that the four gospels should be Matthew, Mark, Luke and John.

Answer 2

A:As far as we know, not one of the ancient gospels was written by a disciple or contemporary of Jesus or Paul. This is as true of the Gospel of Mary as it is of the Gospels of Matthew, Mark, Luke and John. Gospels were selected for inclusion in the New Testament because of their content, not because the Church Fathers had proof of their origins. The four gospels we now have in The Bible were included because they suited the theology of the branch of Christianity that had begun to dominate in the second century and was therefore able to select the canon of books it wished to have in the Bible. The Gospel of Mary reflected teachings of the other main branch of Christianity, Gnosticism, and was therefore unsuited to the New Testament.

Answer 3

Basically because there is no Gospel written by St. Thomas. The "Gospel of Thomas" is a gnostic writing from the 2nd century, and thus not part of the Scriptures. See the explanation at Catholic Answers below: