While certainly affirming our Lord's teaching to go out into the highways and by-ways to seek the lost and of being a light to the world, have you ever run across a situation where you simply cannot put yourself in the presence of a particular individual(s) because of the lifestyle they choose to live? People whose manifest and unrepentant sins are so scandalous that you believe it would be spiritually damaging for you or your family to engage with them in any way? People whom you basically shun or shut out of your daily life intentionally?
We all have these people - and maybe you feel a little bit bad about your approach to them? Maybe you feel conflicted. After all, you remember the "sinners and tax collectors" stuff from the New Testament and the "who is my neighbor?" stuff and you wonder whether it is really just to simply exclude a person from your life because of their sins. After all, you were a sinner and God did not exclude you.
The only sin or evil that is mentioned here is the refusal of a person or persons to listen to the Gospel or be willing to receive a Christian in order to hear the Gospel. If this occurs, Jesus commands the disciples to "shake the dust from your feet"; in New Testament era jargon, this reflects a demonstration of repudiation or separation. Pious Jews used to do this after passing through a Gentile city to demonstrate their repudiation of the Gentile customs they had to endure whilst in a city on business. The command of Christ to do this signifies that the believer repudiates the unbelief of the infidel. But not only is the unbelief repudiated, but the believer must physically separate himself from the presence of the obstinate infidel by "going forth out of that house or city"; St. Paul and Barnabas do just this in Acts 13:50-51 after meeting hostility in Pisidia. They shake the dust off their feet and move on to another city, leaving the unbelievers to themselves.
Note also our Lord not only commands repudiation and physical separation, but pronounces a woeful judgment on the unbelievers.
This is not shunning in the positive sense of a believer refusing to see a scandalous sinner; rather, it is the believer removing himself from the presence of obstinate unbelievers. But the principle is introduced that a physical separation from an obstinate infidel - and that word obstinate is key - is sometimes necessary.
Jesus also discusses shunning in Matthew 18:15-17:
"If your brother sins against you, go and tell him his fault, between you and him alone. If he listens to you, you have gained your brother.But if he does not listen, take one or two others along with you, that every word may be confirmed by the evidence of two or three witnesses. If he refuses to listen to them, tell it to the church; and if he refuses to listen even to the church, let him be to you as a Gentile and a tax collector."
First, note that this is applied to "your brother"; i.e., another member of the Church. That this is evident is denoted by Christ's reference to "the Church" as the authority the two brethren can take their problem to. If the errant brother was not also a member of the Church, why would the Church have jurisdiction to hear the case? So Christ applies this teaching to other Christians, not unbelievers in general.
Second, the obstinacy of the brother who refuses to listen "even to the Church" merits shunning. "Let him be to you as a Gentile and a tax collector" means shun him; it is common knowledge that pious Jews shunned the company and homes of Gentiles and tax collectors, and Jesus' admonition is that one remaining obstinate in his sins is to be shunned by the Church.
Let us go on to 1 Corinthians, where we see St. Paul has taken the concept of physical separation in cases of obstinate refusal to listen and applied it to cases of sexual immorality within the Church:
1 Corinthians 5:19-13
"I wrote to you in my letter not to associate with sexually immoral persons— not at all meaning the immoral of this world, or the greedy and robbers, or idolaters, since you would then need to go out of the world. But now I am writing to you not to associate with anyone who bears the name of brother or sister who is sexually immoral or greedy, or is an idolater, reviler, drunkard, or robber. Do not even eat with such a one. For what have I to do with judging those outside? Is it not those who are inside that you are to judge? God will judge those outside. “Drive out the wicked person from among you.”
Like in Matthew 18, we see the practice of shunning being invoked to deal with cases of obstinate sin within the Church. And in case Jesus' teaching was not clear enough, St. Paul goes to lengths to explain that he is not suggesting that Christians separate from the sinners of the world - for to do that, one would need to leave the world! On the contrary, it is those who call themselves Christian yet persist in sin who must be shunned. Notice also that, contrary to the conventional wisdom of the world, St. Paul assumes that Christians are discerning, judgmental people: "Is it not those who are inside that you are to judge?"
But why do believers in obstinate sin -sexual immorality in this case - deserve to be shunned? Why not extend this to unbelievers as well? After all, sin is sin and scandal is scandal, right?
Well, not really. Adultery is always scandalous, but when adultery occurs in the case of a Christian it is especially scandalous because the Christian ought to know better. This is why St. Peter admonishes, "let none of you suffer as a murderer, a thief, a criminal, or even as a mischief maker" (1 Pet. 4:15), and also why Jesus warns that a Christian who falls into grave sin is in a much worse state than a sinner who was never in a state of grace to begin with (cf. Luke 11:23-26). In other words, there is particular scandal about obstinate sin or unbelief when one should know better. "If your eye is unsound, your whole body will be full of darkness. If then the very light in you is darkened, how dense is that darkness! (Matt. 6:23).
Note that Paul recommends a very strict separation in the case of these obstinate sinners. We are not to "associate" with these people - and as if to make sure we understand how serious Paul is, he specifies that we are not even to eat with such people. He goes on to quote Deut. 17:7, which says "purge the evil from the midst of you" and has reference to the execution of the death sentence against Israelites guilty of worshiping other gods. Given this, it would be difficult to argue in context that Paul's admonition to shun sexually immoral Christians is not meant to be taken literally. This also demonstrates that Paul is not referring to a juridical excommunication - although excommunication is a kind of formal shunning on the part of the whole Church. Rather, he is referring to the way individual Christians are to treat other individual Christians who are habitually sexually immoral.
Finally, let us turn to 2 John 1:7-11 for the next development of the practice. Christ has given us the principle that obstinate unbelievers ought to be separated from, as well as members of the Church who are obstinate sinners; St. Paul uses the example of habitual sexual immorality among Christians as an practical example of Christ's precept and goes to great lengths to state that the separation should be total - we should neither "associate" nor "eat with" such person.
St. John the Apostle applies this to not only immoral Christians, but heretical Christians as well. Let us turn to 2 John 1:7-11:
"Many deceivers have gone out into the world, those who do not confess that Jesus Christ has come in the flesh; any such person is the deceiver and the antichrist! Be on your guard, so that you do not lose what we have worked for, but may receive a full reward. Everyone who does not abide in the teaching of Christ, but goes beyond it, does not have God; whoever abides in the teaching has both the Father and the Son. Do not receive into the house or welcome anyone who comes to you and does not bring this teaching; for to welcome is to participate in the evil deeds of such a person."
St. John is speaking clearly of doctrinal deviations, for he references anyone who "does not bring this teaching." In other words, heretics, those who obstinately refuse to "abide in the teaching of Christ". We are to neither welcome these people nor even let them into our houses. Like St. Paul, St. John advocates a total shunning of the heretic. But unlike Paul, John gives the rationale: "To welcome is to participate in the evil deeds of such a person."
This is an important point. Even if we personally disagree with homosexual acts, if we welcome a practicing homosexual who professes to be a Christian into our homes, we are in fact affirming his wicked lifestyle and thus sharing in his evil deeds. Remember, one of the traditional ways of partaking in the sin of another is by silence. Receiving one into the house signifies a kind of silence regarding the person's errors; unless of course you are visiting with the person for the express purpose of calling them to repentance - the correct context in which to understand Christ's eating with tax collectors and sinners, by the way - but the problem is too many people fraternize with heretical or immoral Christians whilst simultaneously keeping silent about their immoral lifestyles. They thus refuse to perform a spiritual work of mercy while affirming the sinner and thus sharing the guilt of their sins.
On the contrary, shunning is a type of admonition of the sinner, a kind of call to repentance by avoidance of physical communion - symbolizing that the obstinate sinner has broken communion with God and the Church. It is like a personal-social boycott against sin, and as such is actually a spiritual work of mercy.
By the way, St. John does not say this practice applies only to really bad heretics, but to "everyone" who does not abide in the teaching of Christ.
In St. John, we see the kernel of the traditional understanding of the relationship between "heresy" and "obstinacy"; heresy is defined as a kind of obstinate, inflexible refusal to believe or "abide" in sound teaching. The heretic and the habitually immoral Christian are to be shunned because their obstinacy is a scandal and to continue to commune and associate with them as if nothing were wrong would be to make us complicit in their sins. This is why St. Athanasius refused to receive communion with Arius and why St. John the Apostle removed himself from a public building when he learned a notable heretic was inside (St. Irenaeus, Adv. Haer. III.3.4).
So what sorts of practical conclusions can we draw here?
First, there are appropriate situations for actively shunning the company of other people. Who? According to the New Testament, other Christians who are obstinately living in sin, especially sexual immorality, as well as heretics. We do not go out of our way to avoid the sinners of the world - those folks are targets for conversion and anyhow its impossible to get away from them ultimately. But we do expect a certain degree of behavior and fidelity "on the inside" of the Church, to use St. Paul's language. Those Christians who obstinately refuse to maintain it ought to be avoided. What sorts of people in your life fit this description?
Second, that this shunning is physical and total - refusal to associate with, eat with, or even greet these people. How would this look in your life were it put into practice?
Third, that refusal to do so in fact makes us guilty of these people's sins. It is not an act of Christian charity to invite your lesbian niece and her girlfriend over for Christmas dinner while not saying anything to them about their sin. In fact, to do so would make you guilty of sharing in their sin. Examine your conscience here.
Fourth, in all these cases, Christ, St. Paul and St. John are all more interested in preserving the integrity and sanctity of the faithful believer than worrying about the feelings of the obstinate sinner being shunned. So should we.
Fifth, we need to keep this teaching in proper perspective. After a person repents, we are to welcome them back joyfully (cf. Luke 15:7, 2 Cor. 2:6-11, Luke 15:22-24). Furthermore, this cannot be used as an excuse to avoid evangelism. As we said above, this teaching clearly applies to those called by the name of Christ, not unbelievers in need of Christ.
Finally, it is not arrogant judgmentalism or Pharisaism. St. Paul himself affirms that it is our business to judge those "on the inside." Still, such judgments should be made in humility, not out of a sense of superiority.
So do not feel guilty that you did not invite your lesbian niece and her girlfriend to the family party. Put away your nagging questions about whether you ought to attend the third marriage of your Uncle Gary. You are doing the correct thing by shunning these people. To do otherwise is to affirm their evil deeds and partake in them. There is a place for shunning in Catholicism, and if we weren't so paralyzed by seeming judgmental or harsh, we would realize it.
"So shall you purge the evil from your midst." ~Deut. 17:7