Original sin ended with Adam. ‘Adam received words from his Lord, and He relented towards him’ (Quran 2:37). The God of Mercy and Justice cannot punish children for their father’s sin; He even opens the way to our own individual ‘turning’ at every moment of our lives. There is no ‘door of repentance,’ only an open door-frame. Going through it comes naturally to us.
Augustine proposes the ugliest doctrine in the history of religion: an unbaptised infant is damned in the eternal ‘pain of sense’. But for Muslims, we are not genetically-defective cripples, destined to be beaten for a crime we did not commit.
Infinite sin (and is this not rather hard on Adam, the ‘hungry child’?) requires, for Augustine, an infinite sacrifice. God Himself must suffer. Hence Augustine’s church must deify the Messiah, even though the Messiah taught that the father forgave the prodigal son simply when he repented. In the Parables, a vicarious sacrifice is nowhere in sight.
Excerpts from Commentary on the Eleventh Contentions by Abdal Hakim Murad (Tim Winter) pp 1-2