This is a highly controversial topic as there are many people that have a high view of Augustine. However, what He introduced in to the Church is nothing less than Gnosticism. The more I read the ante-Nicean (prior to the council) church writings, the more I see our view of scripture is not nearly as literal as there's was.
Augustine spent years as a disciple of Manichean Gnosticism. This group denied man's free will, man's ability to cease sinning, and that God has pre-determined some for hell and some for Heaven. When Pelagius debated Augustine, Pelagius largely quoted what Augustine believed before he became a disciple of Mani.
Here are a couple of quotes from Church leaders before Augustine;
I find, then, that man was constituted free by God. He was master of
his own will and power…For a law would not be imposed upon one who did
not have it in his power to render that obedience which is due to law.
Nor again, would the penalty of death be threatened against sin, if a
contempt of the law were impossible to man in the liberty of his
will…Man is free, with a will either for obedience of resistance. (c.
207, Vol. 3, pp. 300-301) (Tertullian)
And again, who are they that have been saved, and received the
inheritance? Those doubtless who do believe in God and who have
continued in His love… and innocent children, who have had no sense of
There is set before us life upon our observance [of God’s precepts],
but death as the result of disobedience, and every one, according to
the choice he makes, shall go to his own place, let us flee from
death, and make choice of life. (Ignatius)
We…have believed and are saved by voluntary choice (c. 195, Vol. 2, p.
217) (Clement of Alexandria)
Thus although we are born neither good nor bad, we become on or the
other and having formed habits, we are with difficulty drawn from
them. Pg 273 vol.8 (Clement)
Certain ones of those [Gnostic’s] who hold different opinions misuse
these passages. They essentially destroy free will by introducing
ruined natures incapable of salvation and by introducing others as
being saved in such a way that they cannot be lost. (Origen)
This is a common theme in their writings - and all of these opinions of were formed through a plain literal reading of what scripture plainly says.
Only this have I found: I have discovered that God made men upright,
but they have sought out many schemes. - Ecclesiastes 7:29
And the little ones, whom you said would become captives— your
children who do not know good from evil, will enter the land I give
them and possess it. - Deuteronomy 1:39
But if it is unpleasing in your sight to serve the LORD, choose for
yourselves this day whom you will serve - Joshua 24:15a
“Why are you angry,” said the LORD to Cain, “and why is your face
downcast? If you do what is right, will you not be accepted? But if
you refuse to do what is right, sin is crouching at your door; you are
its object of desire, but you must master it.” - Genesis 4:6-7
The use of force was precipitated because He denied mankind's God given free will. He denied our ability to choose, and put upon mankind a "ruined nature" that had to be baptized out with a sprinkling as a baby.
As some additional resources I highly recommend checking out the scroll publishing channel on YouTube, that has the majority of their audio CD's. I also recommend using the Early Christian Dictionary and comparing it to scripture and what is taught today.
Let God be true, and every man be a liar.