An expert from a Easter Vigil sermon given by St. Augustine wherein he gives a forewarning and comfort to the newly illumined so as to not expect perfect members in the Church before the resurrection:
“So listen to me, O you freshly born children of a chaste mother [the Church]… Because you were once darkness, but now light in the Lord, stick close to the children of light; and let me put it quite plainly: stick close to those of the faithful who are good. Because there are, you see, and this is a sad and sorry fact, a number of the faithful who are bad. They are the faithful who are called so, and are not really so. They are the faithful by whom the sacraments of Christ are misused… They perish themselves by living bad lives; while they ruin others by setting them the example of living bad lives. So you, then, dearly beloved, see you don’t join such people. Seek out the good ones, stick close to the good ones, be good ones yourselves.
“𝑫𝒐𝒏❜𝒕 𝒃𝒆 𝒔𝒖𝒓𝒑𝒓𝒊𝒔𝒆𝒅, either, at how many bad Christians there are, who fill the church, who communicate at the altar, who loudly praise the bishop or the priest when he preaches about good morals… They can be with us in the Church of this time; but in that Church which will come into being after the resurrection, they will be unable to be gathered in with the saints. The Church of this time, you see, is compared to a threshing-floor, having on it grain mixed with chaff, having bad members mixed with good…
“You older faithful, you listen too to what I’m saying. Any of you who are grain, rejoice with trembling, and 𝒔𝒕𝒂𝒚 𝒘𝒉𝒆𝒓𝒆 𝒚𝒐𝒖 𝒂𝒓𝒆, and don’t leave the threshing-floor. Don’t attempt, on your own judgment, to shake yourselves free, as it were, from the chaff; because if you want to separate yourself now from the chaff, you won’t be able to stay on the threshing-floor. And when that one comes who distinguishes infallibly between grain and chaff, he won’t carry up to the granary anything he doesn’t find on the threshing-floor. So it will be no good at that time for grains to boast about the ears of wheat they come from, if they have left the threshing-floor. That granary will be filled and closed. Anything left outside will be gutted by fire.
“So then, dearly beloved, if you are good, you must put up with the bad… 𝑳𝒊𝒔𝒕𝒆𝒏 𝒕𝒐 𝒎𝒆, 𝒈𝒓𝒂𝒊𝒏𝒔; 𝒍𝒊𝒔𝒕𝒆𝒏 𝒕𝒐 𝒎𝒆, 𝒕𝒉𝒐𝒔𝒆 𝒐𝒇 𝒚𝒐𝒖 𝒘𝒉𝒐 𝒂𝒓𝒆 𝒘𝒉𝒂𝒕 𝑰 𝒅𝒆𝒔𝒊𝒓𝒆 𝒚𝒐𝒖 𝒕𝒐 𝒃𝒆. 𝑫𝒐𝒏❜𝒕 𝒍𝒆𝒕 𝒕𝒉𝒆 𝒎𝒊𝒙𝒕𝒖𝒓𝒆 𝒐𝒇 𝒉𝒖𝒔𝒌𝒔 𝒅𝒆𝒑𝒓𝒆𝒔𝒔 𝒚𝒐𝒖; 𝒕𝒉𝒆𝒚 𝒘𝒐𝒏❜𝒕 𝒃𝒆 𝒘𝒊𝒕𝒉 𝒚𝒐𝒖 𝒇𝒐𝒓𝒆𝒗𝒆𝒓.”
Augustine, Sermon 223, At the Easter Vigil; citation from Augustine: Essential Sermons (Hyde Park, NY: New City Press, 2007), 277-279.
S. Anselm, who is both a Saint and Doctor in the Catholic Church, states the following in dedicating his book on the Holy Trinity to the Pope. He writes: ‘Forasmuch as the providence of God has chosen your Holiness, to commit to your custody the life and faith of Christians, and the government of His Church, to no other can reference be more rightly made, if so be anything contrary to the Catholic faith arise in the Church, that it may be corrected by his authority; nor to any other can anything which may be written against such errors be more safely submitted, that by his prudence it may be examined.’ Again: ‘Let those who despise the Christian decrees of the Vicar of Peter, and in him the decrees of Peter and of Christ, seek for other gates of the kingdom of heaven; for certainly they shall not enter in by those, the keys of which the Apostle Peter bears.’
Source: Henry Edward Manning – https://en.wikisource.org/wiki/Petri_Privilegium/II/Chapter_3#77