not sure if you received a response from elsewhere but figured there's no harm in replying
so Augustine's Theodicy is an attempt to explain the existence of evil right, but the soul-deciding part is the idea that humans have the choice to turn back to God, through the salvation of Jesus
the 'turn back to God' bit I believe is because Augustine believed humans were created perfect but the fall of Adam and Eve was the first sin of all mankind since we were all present 'in the loins of Adam'
but yeah, its essentially what you said