A good model to contemplate in our factional Church is a saint such as Paul, caught in factional riptides very like our own, yet able to navigate those waters successfully.
It is interesting to note that St. Paul does not spend a lot of time fretting about who is and is not the “real Catholic.” That’s because he begins with the recognition that nobody, least of all he, is a real Catholic or a real Christian or anything other than a sinner saved by the bleeding charity of the Crucified Christ. Therefore, of himself, he writes:
“I am grateful to him who has strengthened me, Christ Jesus our Lord, because he considered me trustworthy in appointing me to the ministry. I was once a blasphemer and a persecutor and an arrogant man, but I have been mercifully treated because I acted out of ignorance in my unbelief. Indeed, the grace of our Lord has been abundant, along with the faith and love that are in Christ Jesus. This saying is trustworthy and deserves full acceptance: Christ Jesus came into the world to save sinners. Of these I am the foremost. But for that reason I was mercifully treated, so that in me, as the foremost, Christ Jesus might display all his patience as an example for those who would come to believe in him for everlasting life.” (1 Tm 1:12-16)
Meanwhile, his diagnosis for the rest of us is not much cheerier:
“... Jews and Greeks alike that they are all under the domination of sin, as it is written: ‘There is no one just, not one, there is no one who understands, there is no one who seeks God. All have gone astray; all alike are worthless; there is not one who does good, [there is not] even one. Their throats are open graves; they deceive with their tongues; the venom of asps is on their lips; their mouths are full of bitter cursing. Their feet are quick to shed blood; ruin and misery are in their ways, and the way of peace they know not. There is no fear of God before their eyes’” (Rom 3:9-18)
In short, St. Paul looks on the attempt to figure out who is winning the Spiritual Superiority Sweepstakes as something like the dying patients in a cancer ward vying for the title of “Least Terminal.” That’s a healthy place for anyone to start, and it is something hell is very eager to stop.
C.S. Lewis’ demonic Uncle Screwtape in “The Screwtape Letters” comments on this from hell’s perspective when he tells his nephew Wormwood (a junior demon out in the field attempting to seduce his first human “patient” to damnation):
“One of our great allies at present is the Church itself. Do not misunderstand me. I do not mean the Church as we see her spread out through all time and space and rooted in eternity, terrible as an army with banners. That, I confess, is a spectacle which makes I our boldest tempters uneasy. But fortunately it is quite invisible to these humans. … Make [your patient’s] mind flit to and fro between an expression like ‘the body of Christ’ and the actual faces in the next pew. It matters very little, of course, what kind of people that next pew really contains. You may know one of them to be a great warrior on the Enemy’s side. No matter. Your patient, thanks to Our Father below, is a fool. Provided that any of those neighbors sing out of tune, or have boots that squeak, or double chins, or odd clothes, the patient will quite easily believe that their religion must therefore be somehow ridiculous. … [I]f the patient knows that the woman with the absurd hat is a fanatical bridge-player or the man with squeaky boots a miser and an extortioner — then your task is so much the easier. All you then have to do is to keep out of his mind the question ‘If I, being what I am, can consider that I am in some sense a Christian, why should the different vices of those people in the next pew prove that their religion is mere hypocrisy and convention?’ You may ask whether it is possible to keep such an obvious thought from occurring even to a human mind. It is, Wormwood, it is! Handle him properly and it simply won’t come into his head.”
Not the laity’s place
Does that mean that St. Paul doesn’t care what we believe or do? Certainly not. His letters are full of instructions about truth and falsehood, right and wrong. And when the situation really calls for it, he is not afraid to expel somebody from fellowship.
But note that such expulsions are extremely rare for St. Paul. Also, they are done with an eye to the salvation, not the damnation, of the sinner. And finally, they are never to be done by laypeople. So, the first thing the ordinary Catholic should note is that, as far as booting people from communion goes, unless he is a bishop or somebody acting on a bishop’s authority (in other word, not a layperson) we have no business deciding who needs to be shown the door.