A probable reason for his rejecting them is their strong teaching against Gnostic beliefs.

In context of Gnostic beliefs, Gnostic writings use Mary to illustrate a disciple's spiritual relationship with Jesus, making any physical relationship irrelevant.

The Sibylline Oracles are a valuable source for information about Classical mythology and early first millennium Gnostic, Jewish and Christian beliefs.

Christian orthodoxy rejected the second century Gnostic belief that Genesis was purely allegorical, but without taking a purely literal view of the texts.

By the twelfth century, a resurgence in Gnostic or mystical belief began to arise, taken up in secret by the same emperors who had once beaten it down.

It's also when you mentioned there was a resurgence in Gnostic belief, creating a schism between emperors and the papacy.

Thomas represented Gnostic belief.

It became the foundation for astrology and the cornerstone for Gnostic belief.

A further insight into Gnostic beliefs is provided by sources dealing with Manicheism, one of the most famous Gnostic sects in late antiquity.