Not on your life. Though we had fragments of it earlier, a complete copy of the so-called Gospel of Thomas was discovered in 1945. Once scholars had a copy of the whole thing, it was possible to see it for what it was: yet another gnostic-influenced "gospel" written in the second or third century, long after the canonical gospels were penned.
The Gospel of Thomas presents itself as a collection of sayings of Christ as written by Thomas the apostle. A few of these sayings are genuine because they were taken from the canonical Gospels. Others combine bits of things said in the true gospels. And still others are wholly made up, not only lacking any basis in the gospels but also contradicting things taught in them.
Consider, for example, the final saying Thomas contains: "Simon Peter said to them, ‘Make Mary leave us, for females don’t deserve life.’ Jesus said, ‘Look, I will guide her to make her male, so that she too may become a living spirit resembling you males. For every female who makes herself male will enter the kingdom of heaven’" (Thomas 114).
This is just wacky. Jesus was a great respecter of women as women (i.e., without them having to become like men). After all, as the Creator, he himself had "made them male and female" (Mt 19:4). And so whether one is a man or a woman makes no difference in salvation. As St. Paul said, "There is neither male nor female; for you are all one in Christ Jesus" (Gal 3:28).
The so-called Gospel of Thomas is a fake. It was written between one and two centuries after the apostle Thomas’s death. It contains some authentic sayings of Jesus because it is partially based on the canonical Gospels. It contains a bunch of stuff that is silly. It wasn’t written under divine inspiration. It doesn’t belong in the Bible.
Hollywood has decided to use this literary curiosity as the latest tool to portray the Catholic Church as sinister, conspiracy-ridden, and oppressive and, by extension, to portray all of Christianity in a negative light. The plot of the movie Stigmata has nothing to do with how the Gospel of Thomas was actually discovered.
I must concur with film critic Roger Ebert’s assessment:
Stigmata is possibly the funniest movie ever made about Catholicism—from a theological point of view. . . . The film, a storehouse of absurd theology, has the gall to end with one of those "factual" title cards, in which we learn that the "Gospel of St. Thomas," said to be in Christ’s words, was denounced by the Vatican in 1945 as a "heresy." That doesn’t mean it wouldn’t be out in paperback if there were a market for it. It does mean the filmmakers have a shaky understanding of the difference between a heresy and a fake.