From Fr. John Zuhlsdorf over at his blog what does the prayer really say (wdtprs) we have a post about what then Cardinal Ratzinger thought was going to happen to the Church.
The church will become small and will have to start afresh more or less from the beginning.
She will no longer be able to inhabit many of the edifices she built in prosperity. As the number of her adherents diminishes . . . she will lose many of her social privileges. . . As a small society, [the Church] will make much bigger demands on the initiative of her individual members….
It will be hard-going for the Church, for the process of crystallization and clarification will cost her much valuable energy. It will make her poor and cause her to become the Church of the meek . . . The process will be long and wearisome as was the road from the false progressivism on the eve of the French Revolution — when a bishop might be thought smart if he made fun of dogmas and even insinuated that the existence of God was by no means certain . . . But when the trial of this sifting is past, a great power will flow from a more spiritualized and simplified Church. Men in a totally planned world will find themselves unspeakably lonely. If they have completely lost sight of God, they will feel the whole horror of their poverty. Then they will discover the little flock of believers as something wholly new. They will discover it as a hope that is meant for them, an answer for which they have always been searching in secret.
And so it seems certain to me that the Church is facing very hard times. The real crisis has scarcely begun. We will have to count on terrific upheavals. But I am equally certain about what will remain at the end: not the Church of the political cult, which is dead already, but the Church of faith. She may well no longer be the dominant social power to the extent that she was until recently; but she will enjoy a fresh blossoming and be seen as man’s home, where he will find life and hope beyond death.
Remember this is from 1969. You can get this book Faith and the Future published by Ignatius Press in 2009.