Well, I've heard that both the book of Revelation and many things Paul taught are Gnostic..
Especially Paul on his teachings to deny the body...that's to be clean is to be free of fleshly desires....going against Gods teachings to be fruitful and multiply.
The Book of John and Revelation are both Gnostic in origin. Gnosticism is a pagan, dualistic system (God verses Satan, etc. from Zoroastrianism and other Eastern religions) that heavily influenced the Apostle Paul and via the Manichees Saint Augustine. The Gnostics were declared heretics after Nicaea in 325 CE and butchered. The Zoroastrians in Persia would be butchered by Islam. While Gnosticism and Zoroastrianism are not really monotheistic, their infiltration of the church is very great and still haunts us today.
And crept into other beliefs also.http://www.rotten.com/library/religion/gnosticism/