I took a bite and immediately spit it out; the food had turned bad. Something was definitely past its expiration date. We can thank God for the sense of taste; not just for the enjoyment of good foods, but also for the recognition of things that are bad for us (though we rarely think of this special gift, we appreciate it when we need it!). I am told that there are no poison plants that taste pleasant, and most have a horrible taste. God has granted us the ability to recognize when something needs to be spit out. Yet, there are some people whose taste buds have been ruined for some reason, and they might not recognize something that tastes bad.
Just as physical taste can tell us that something is wrong, so also is there a spiritual action that does the same thing. In every person's spirit there is a conscience that tells them that they have done something wrong. Now it is possible for someone's conscience to become so calloused by sinful behavior that he does not feel any sensations of guilt. This is actually one of the deepest points of sinful degeneration (as St. Paul points out: cf. 1 Corinthians 8:10, 1 Timothy 1:19 & 4:2, and Titus 1:15); when a person's conscience is so damaged that he no longer senses the evil of his actions.
The Catholic Church today is filled with fights and divisions. The list of disagreements is more than I can put here. Many of these quarrels are likely not necessary, and can be resolved if we, as God's people, would take advantage of sacramental grace and reconsider how we disagree. Ignoring our conscience for the sake of winning and argument is never right. This means that we each need to do some self examination and determine whether our conscience is rightly formed, and whether we are following the path of holiness in our disagreements.
There are a number of ways that we can recognize damage to a person's conscience. The most obvious is when a person openly says that he has no remorse or guilt for his sinful behavior. Of course, there are those who will say that they do not have any feelings of remorse (when they actually do have them), and they do this because they are trying to cover up their pain. Those whose consciences are truly "seared" are not always this overt in their behavior though. Sometimes--in the name of righteousness--there are those whose consciences do not recognize one of the worst expressions of selfish pride: divisiveness.
In more than one place in Sacred Scripture we find the references to the sin of divisiveness (Leviticus 19:16, Romans 16:17, Galatians 5:20, Titus 3:10, etc.). In essence, any behavior that is done intentionally to cause antagonism between one brother and another is considered to be divisive. There are certainly those who behave divisively, but are doing so out of ignorance, or they somehow do not realize that they are being divisive. Although still genuinely divisive, they do not hold the same level of culpability as do those who cause division purposefully. To cause division is the same as destroying love and encouraging hate.
So we should then ask the straightforward question: what is it that causes quarrels and divisions? There are many types of circumstances where people become quarrelsome, but they can all be summarized as: one person thinks he is smarter than another. If you and I disagree about something and neither is willing to change his mind, then we both think we are smarter than the other. If neither party insisted on his or her way, then there would be no quarrel. The disagreement can be caused by a mere misunderstanding, or it can come from a prideful unwillingness to be humble. The first can easily be resolved by just discussing the matter (assuming both parties are willing to do so). The second, however, is a much deeper problem.
The Scriptures refer to the attitude of "I know more than you and I'm unwilling to change" as "devilish wisdom" (cf. James 3:15). In other words, it is a wrong manner of thinking that causes one to believe things that are errant, and stubbornly to insist on maintaining that belief. The Apostle James says that this worldly wisdom causes "bitter jealousy and selfish ambition" (3:14), and that leads to "wars" and "fightings" (4:1). Thus, this kind of quarrel is caused by someone falling into a prideful foolishness and refusing to repent. Once a person is overtaken by worldly wisdom, if his conscience is seared (as above) then it will be even harder for him to find penitence since he becomes "stuck" in his divisive behavior.
For those who are immature in their faith, it may be hard to discern the difference between stubborn divisiveness and faithful perseverance. The main point that will help us to see the difference is the manner of someone's disagreement. We need to look for who is expressing holiness and purity as Christ did when He was attacked. If someone angrily demands that he is right and runs around telling others about it to garner support, he has clearly fallen to divisiveness. If, on the other hand, someone remains humble, accepting the wrongful treatment with a cheerful expression of another opinion on the matter, that is the one who is remaining in the grace of Christ.
Of course, as mentioned above, not all who fall into divisive behavior have a completely "seared conscience". There are, by the grace of God, some who eventually see their behavior for what it is, and they repent of it. For which, we should give thanks to God. How do we help someone like this to find repentance? There is no one right method, for each person is different and will need a unique grace to help him. This means that if you know someone like this (and he is still talking to you) then you should do your best to seek out how to get through to him so that he can return to faithfulness.
Are you currently in a quarrel with someone? Have you made the presumption that you are in the right and the other is wrong? Have you even given a moment of consideration that your reasoning may be wrong ("devilish wisdom") and that you may need to change your position and admit error? That can be very hard to do, of course, but it always leads to greater holiness. As the people of God we should never presume upon our own brilliance, but always be willing to ask "is it me?" "did I make the mistake?" "how can I do better?" Imagine what differences of opinion would look like if every one of us asked these kinds of questions from the start!