Augustine is right about some things and not as right about others. I'd like to see your source for this exact quote.
Certainly.
“I would not believe in the Gospel myself if the authority of the Catholic Church did not influence me to do so.”
Against the letter of Mani, 5,6, 397 A.D.
This Church is Holy, the One Church, the True Church, the Catholic Church, fighting as she does against all heresies. She can fight, but she cannot be beaten. All heresies are expelled from her, like the useless loppings pruned from a vine. She remains fixed in her root, in her vine, in her love. The gates of hell shall not conquer her.”
Sermon to Catechumens, on the Creed, 6,14, 395 A.D.
“We must hold to the Christian religion and to communication in her Church which is Catholic, and which is called Catholic not only by her members but even by all her enemies. For when heretics or the adherents of schisms talk about her, not among themselves but with strangers, willy-nilly they call her nothing else but Catholic. For they would not be understood unless they distinguish her by this name which the whole world employs in her regard.”
The True Religion, 7,12, 397 A.D.
“By the same word, by the same Sacrament you were born, but you will not come to the same inheritance of eternal life, unless you return to the Catholic Church.”
Sermons, 3, 391 A.D.
“What the soul is to man’s body, the Holy Spirit is to the Body of Christ, which is the Church. The Holy Spirit does in the whole Church what the soul does in all members of one body. But see what you must beware of, see what you must take note of, see what you must fear. It happens that in the human body, or rather, off the body, some member, whether hand, finger, or foot, may be cut away. And if a member be cut off, does the soul go with it? When the member was in the body, it lived; and off, its life is lost. So too, a Christian man is Catholic while he lives in the body; cut off, he is made a heretic; the Spirit does not follow an amputated member.”
Sermons, 267, 4, 391-430 A.D.
“The Catholic Church is the work of Divine Providence, achieved through the prophecies of the prophets, through the Incarnation and the teaching of Christ, through the journeys of the Apostles, through the suffering, the crosses, the blood and the death of the martyrs, through the admirable lives of the saints. When, then, we see so much help on God’s part, so much progress and so much fruit, shall we hesitate to bury ourselves in the bosom of that Church? For starting from the Apostolic Chair down through successions of bishops, even unto the open confession of all mankind, it has possessed the crown of teaching authority.”
The Advantage of Believing, 391 A.D.
http://home.inreach.com/bstanley/august.htm
You understand, Dr. E. that a demonic ploy to overthrown the Catholic Church cannot win? The Lord has promised us that. You may wish to reconsider.