The Struggle for Holiness & the "Perfect Church"
This does not mean that everything must be left undisturbed and endured as it is. Endurance can also be a highly active process, a struggle to make the Church herself more and more that which supports and endures. After all, the Church does not live otherwise than in us; she lives from the struggle of the unholy to attain holiness, just as of course this struggle lives from the gift of God, without which it could not exist. But this effort only becomes fruitful and constructive if it is inspired by the spirit of forbearance, by real love. And here we have arrived at the criterion by which that critical struggle for better holiness must always be judged, a criterion that is not only not in contradiction with forbearance but is demanded by it. This criterion is constructiveness. A bitterness that only destroys stands self-condemned. A slammed door can, it is true, become a sign that shakes up those inside. But the idea that one can do more constructive work in isolation than in fellowship with others is just as much of an illusion as the notion of a Church of “holy people” instead of a “holy Church” that is holy because the Lord bestows holiness on her as a quite unmerited gift.
Ratzinger, J. (2004). Introduction to Christianity (Revised Edition). (J. R. Foster, Trans.) (pp. 343–344). San Francisco: Ignatius Press.