Augustine didn't move away from the early church. Since you deny that scripture itself is a development, there is little point using that logic. The claim that the Church invented one doctrine to bolster another is just sheer stupidity.It is impossible for the Church to operate like that.
ST. IRENAEUS (c. 180 AD)
....having become disobedient, [Eve] was made the cause of death for herself and for the whole human race; so also Mary, betrothed to a man but nevertheless still a virgin, being obedient, was made the cause of salvation for herself and for the whole human race....Thus, the knot of Eve's disobedience was loosed by the obedience of Mary. What the virgin Eve had bound in unbelief, the Virgin Mary loosed through faith. ...But this man [of whom I have been speaking] is Adam, if truth be told, the first-formed man....WE, however, are all FROM him; and as WE are FROM him, WE have INHERITED his title [of sin]. ...Indeed, THROUGH the first Adam, WE offended God by not observing His command. Through the second Adam, however, we are reconciled, and are made obedient even unto death. For we were debtors to none other except to Him, whose commandment WE transgressed at the beginning. (Against Heresies 3:22:4; 3:23:2; 5:16:3)
TERTULLIAN (c. 200 AD)
Finally, in every instance of vexation, contempt, and abhorrence, you pronounce the name of Satan. He it is whom we call the angel of wickedness, the author of every error, the corrupter of the whole world, through whom MAN was deceived in the very beginning so that he transgressed the command of God. On ACCOUNT of his transgression MAN was given over to death; and the WHOLE HUMAN RACE, which was INFECTED by his SEED, was made the TRANSMITTER of condemnation. (The Testmiony of the Soul 3:2, c. 200 AD)
"Because by a man came death, by a man also comes resurrection" [1 Cor 15:21]. Here, by the word MAN, who consists of a body, as we have often shown already, I understand that it is a fact that Christ had a body. And if we are all made to live in Christ as WE were made to DIE IN ADAM, then, as in the flesh we were made to DIE IN ADAM, so also in the flesh are we made to live in Christ. Otherwise, if the coming to life in Christ were not to take place in that same substance in which WE DIE IN ADAM, the parallel were imperfect.
(Against Marcion 5:9:5, c. 210 AD)
ORIGEN (c. 244 AD)
EVERYONE in the world FALLS PROSTRATE under SIN. And it is the Lord who sets up those who are cast down and who sustains all who are falling [Psalm 145:14]. IN ADAM ALL DIE, and THUS the world FALLS PROSTRATE and requires to be SET UP AGAIN, so that in Christ all may be made to live [1 Cor 15:22]. (Homilies on Jeremias 8:1)
EVERY SOUL that is BORN into flesh is SOILED by the filth of wickedness and SIN....And if it should seem necessary to do so, there may be added to the aforementioned considerations [referring to previous Scriptures cited that we all sin] the fact that in the Church, Baptism is given FOR THE REMISSION OF SINS; and according to the usage of the Church, Baptism is given EVEN TO INFANTS. And indeed if there were nothing in infants which REQUIRED a remission of sins and nothing in them pertinent to forgiveness, the grace of Baptism would seem SUPERFLUOUS. (Homilies on Leviticus 8:3)
The Church received from the Apostles the tradition of giving Baptism EVEN TO INFANTS. For the Apostles, to whom were committed the secrets of divine mysteries, knew that there is in everyone the INNATE STAINS OF SIN, which must be WASHED AWAY through water and the Spirit [cf. John 3:5; Acts 2:38]. (Commentaries on Romans 5:9)
Please quote Augustine as to exactly how he "moved away" from the essential understanding of the early church.
You didn't answer my question.
Is truth relative?