It is the human spirit that is of and from God Jn.3:6, the soul is created by God Gen.1:27. We are souls, just as angels and demons are spirits. The soul reflects God but is not of His substance like our spirit. The soul is the seat of our personality and it is where we build character. The body contains the sin nature, the corruption inherited down the line from Adam, entrapping the soul in it's self-serving instincts. That, coupled with the cosmic system of thinking Rom.12:2 and the pressure applied by direct demonic attack (in some cases), serves to lead the soul astray and into corruption.
But grace intervenes in that process by controlling the flesh, providing light and truth and hedging the devil out so the soul can decide for itself how to respond to God according to it's own desires. Contrary to TULIP belief, not all men desire darkness for there are those who learn from the Father when He applies His grace and are drawn to Him for this is the normal state of what God intended for man. The soul is not born corrupt as the TULIP adherent demands and just how corrupt that soul becomes depends on how they respond to God's grace in the process. Some are more stubborn than others.
John 6:44-45
44 No one can come to Me unless the Father who sent Me draws him; and I will raise him up at the last day. 45 It is written in the prophets, ‘And they shall all be taught by God.’ Therefore everyone who has heard and learned from the Father comes to Me.