Hi Terry,
Much of the religious beliefs (Judaism, Christianity, Islam) owe their origins to the revolutions of this period commencing with the 3rd century BCE. Most of the OT's ideas were formed some 300 years earlier, by the 6th century BCE.
These new ideas, such as apocalyptic, eschatology, messianism, personified evil spirits (Satan,Mastema, Beliar, demons, etc.), war in heaven, final judgement, and so on, find their origins in this latter ("intertestamental") period, not in the OT. The period created sects such as the Pharisees, Essenes, etc., etc.
One of the canonised books that was influenced by this environment is the Book of Daniel. It was written in the 2nd century BCE, often drawing on imagery from books such as Enoch, Jubilees.
Doug