Some people think that Augustine has an overly spiritualized notion of the church. I don’t think that’s true, as familiarity with his usually very concrete preaching should make clear. An example is below, where he addresses the question of whether the church can be said to be “without stain or wrinkle” (Eph 5:27). Behind his answer to the Manicheans’ question is the conviction that when you are speaking about the church, you are speaking about the community of believers.
But, the Manicheans say, by what likeness can the flesh be compared to the Church. Surely the Church does not lust against Christ? Did not the Apostle say, “The Church is subject to Christ” (Eph 5:24)?
Of course, the Church is subject to Christ because the spirit is lusting against the flesh so that the Church may in every way be made subject to Christ; but the flesh is also lusting against the spirit because the Church has not yet received the perfect peace promised her. The Church is made subject to Christ as a pledge of salvation, and the flesh lusts against the spirit because she is weak from illness. It was to members of the Church, after all, that the Apostle said: “Walk in the spirit, and do not fulfill the lusts of the flesh. For the flesh lusts against the spirit, and the spirit against the flesh; for these are opposed the one to the other so that you do not do what you wish to do” (Gal 5:16-17). These things were certainly said to the Church, and if it were not subject to Christ, then in it the spirit would not be lusting against the flesh through self-control. That is why they were able to avoid fulfilling the lusts of the flesh, even while, because the flesh lusts against the spirit, they could not do the things they wished, that is, not have the lusts of the flesh themselves.
But then, why should we not confess that in spiritual people the Church is subject to Christ, but in carnal people it still lusts against Christ? Were they not lusting against Christ to whom it was said, “Has Christ been divided?” (1 Cor 1:13) and, “I could not speak to you as to spiritual people but as to carnal people, as to little children. I gave you milk to drink, not meat; for you were not yet able. But even now you are not able, for you are still carnal. For since there is among you envy and contention, are you not still carnal?” (1 Cor 3:1-3). Against whom does envy and contention lust but against Christ? Christ heals these lusts of the flesh in his own, but he loves them in no one. That is why as long as the Church has such members, it is not yet without spot or wrinkle.
To those sins are added also those for which the voice of the Church prays every day, “Forgive us our debts” (Mt 6:12). Lest we think that spiritual people are exempt from these sins, it was not a carnal person nor even just any one of the spiritual people, but he who leaned against the breast of the Lord, the one whom Jesus loved more than the others (Jn 13:23), who said: “If we say that we have no sin, we deceive ourselves, and the truth is not in us” (1 Jn 1:8). Every sin involves lust against righteousness, more in a greater sin, less in a lesser sin. And it was of Christ that it was written: “Who was made by God for us wisdom and righteousness and sanctification and redemption” (1 Cor 1:30). Without doubt, then, every sin involves lusting against Christ.
But when he who heals all our sicknesses shall have led his Church to the promised healing of its sickness, then in none of his members will there be the slightest spot or wrinkle. Then the flesh will not in any way lust against the spirit, and there will be no reason for the spirit to lust against the flesh. Then all this conflict will come to an end; then there will be the highest concord between the two substances to the point that no one then will be carnal and even the flesh itself will be spiritual. Consider, therefore, what everyone who is living in accordance with Christ does with his own flesh – he lusts against its evil lust; he restrains it so that it may be healed; he controls it as long as it is not healed, and he nourishes and cherishes its good nature, since “no one ever hated his own flesh” (Eph 5:29).
All this is what Christ does with the Church, if one may compare little things with bigger ones. For he rebukes and restrains it so that impunity does not cause it to puff out and burst,, and he consoles it and raises it up so that it does not sink from the weight of its weakness. That is why the Apostle said: “But if we were to judge ourselves, we would not be condemned; but when we are judged, we are disciplined by the Lord lest we be condemned with this world” (1 Cor 11:31-32). And a Psalm says: “In accord with the multitude of my griefs in my heart, your consolations have gladdened my soul” (Ps 93:19). Our hope is that our flesh will be perfectly sound and unopposed when the Church of Christ will be secure, safe from all fear. (Augustine, De continentia, 25; PL 40, 366-67).