The Pauline Epistles
It has been hypothesized by scholars such as Hyam Maccoby and Elaine Pagels - as well as the mystic Timothy Freke, that Paul of Tarsus was a Gnostic who developed the early Christian church as a mystery religion with a Jewish flavour, and that elements of this church forgot or misunderstood the mystery elements, largely abandoned its Jewish foundation, and took up literal interpretation of the text.
Their argument for Paul being a gnostic is based on arguments about the authorship of the Pauline Epistles. The pastoral epistles (those to Timothy and Titus), are generally acknowledged as being clearly anti-gnostic, and the second Epistle to the Thessalonians clearly refutes certain gnostic interpretations of the first Epistle to the Thessalonians.
Read more about this topic: Gnosticism And The New Testament