St. Augustine (and Vatican Council II, which cited him) made the classical remark that “a person possesses the Holy Spirit to the extent of his love for Christ’s Church” (OT, no. 9). Jesus in the New Testament so identifies himself with the Church he founded and loved into being that he is able to say that “he who hears you, hears me, and he who rejects you, rejects me” (Lk 10:16); and “as long as you did it to the least of mine, you did it to me” (Mt 25:40). It has been a striking trait of the saints through the centuries, even into our own day, that men and women of deep prayer, genuine prayer, are outstanding in their love for the Church, the temple of the Holy Spirit.
—from Prayer Primer: Igniting a Fire Within by Fr. Thomas Dubay, S.M. – Ch. 17: Assessing Progress