This was for Augustine a great change from the Manichean theory of good and evil being equally existent - a duality that he accepted when he had been a Manichean in Carthage, in Rome, and briefly - but less so - just after he had arrived in Milan.
This view, in which the goodness of individual things varies but everything is part of a whole from the point of view of God, allowed Augustine to answer Manichean challenges about the source of evil.
Augustine stated that it had been the books of the Neo-Platonists that enabled him to accept the Gospels and the teachings of the Church as both intellectually coherent and of value personally.
Augustine integrated well his Neo-Platonic philosophy with Christian theology and spiritual tradition.
Good examples of this are his development of the idea of interiority as both a philosophical and a spiritual term, and his emphasis on the reality of the inner life.
These are a blending of both his Platonic heritage and the Scriptural tradition.
As well, his Neo-Platonist background allowed Augustine to be a "bridge" in another important sense as well.
Not only did he bridge the intellectual tension between classical philosophy and Christian theology in the way outlined above, but also he helped to reconcile the more theological expression of the Christian faith as found in Milan with the more devotional Christian religion that operated in the rural areas of North Africa.
In this way, assisted by his intellectual contact with the Neo-Platonists and with Ambrose in Milan, Augustine succeeded in bringing together parts of the classical philosophy of his youth and the popular - and almost anti-intellectual - Christian faith of his quite provincial congregation in Hippo.
During the years around his conversion. In the 380s and 390s, Augustine’s writings are heavily dependent on a fundamentally Platonic view of the world (world view), of human nature (his anthropology) and human destiny (Christian life).
In the Milan of Bishop Ambrose. He had encountered a form of Christianity deeply coloured by the conceptual structures of Platonist origin, and had no conflict between his newly-accepted views of the world, of the soul and of good and evil that were grounded in Neoplatonism.
A tension began to open in the mid-390s, however, when his deepened understanding of the Scriptural writings of Saint Paul questioned the compatibility of the Platonic and Pauline conceptual frameworks. Although Augustine then made a huge shift in his spiritual and intellectual mindset, Platonic philosophy still remained an important underpinning within his writings.