Western Christianity is an extension of Augustinianism, concepts like original guilt and double predestination are Augustinian in origin and directly come from Manicheanism.
>"In Manichaeism, Primeval Man (the first human) used free will to abandon his position in the realm of light and went down into matter and darkness. Escape then became impossible…. Mani invented Manichaeism to be a syncretistic (a combined) religion for all persons worldwide by combining Judaism and Buddhism, then adding Christianity…Mani also borrowed the concept of humanity's total inability to respond to God from the ancient Indo-Mesopotamian Maitrāyana Upanishad IV. This work describes humans as robbed of freedom, imprisoned, drugged by delusion, and in deepest darkness. "He awakens Adam from the sleep of death, shakes him, opens his eyes, raises him up, exorcises demons to free him of demon possession, shows him all of imprisoned [physical] matter and suffering light soul. The Redeemer commands (an awakening from drunken slumber) and then gives what he commanded by granting grace (in order to gaze upon deity): "The Redeemer, the just Zoroaster, spake thus with his soul: 'Deep is the drunkenness in which thou slumberest, awake and gaze upon me! Grace upon thee from the world of peace whence for thy sake I am sent.'" (M.7.82–118, Mir. M. III, p.27).
>Foundations of Augustinian Calvinism, pg 24
>Fortunatus the Manichaean also cited John 14:6 to prove unilateral determinism, "No one can come to the Father except through me," since "He chose souls worthy of himself for his own holy will … and were imbued with a faith" (Against Fortunatus the Manichaean 3). Augustine defended the Christian view by mocking the Manichaean god: "corrupted and worn out I have lost my free choice. You know the necessity that has pressed me down. Why do you blame me for the wounds I received?" (cf., Sermons 12.5, 100.3). Augustine does not cite these verses until after 412 CE when he uses the Manichaean interpretations to prove his new total inability/incapacity for human faith (Grace and Fee Will 10, Against the Two Letters of the Pelagians 4.13–16, ep.186.38).
>Foundations of Augustinian Calvinism, pg 56