The Gospel of Thomas does not seem to be like the rest. It is generally believed to be Gnostic since it ascribes things to being " secret" and shows Jesus as not answering direct questions about his divinity when every other Gospel clearly states that Jesus said he was the Son of God. Therefor it has been decided over time that it is not a true account of things since it is not corroborated by anything else. Even the secular historians of them time called Jesus a sorcerer. They were aware he did amazing things.