Answer
To be sectarian is to possess a limited range of interest, purpose, or scope, or to be devoted to a particularly narrow tradition or belief system. The word sectarianism comes from the root sect, from which also comes the word section. Often, religious or political groups split into smaller “sections” called “sects.” Ideological conflicts can arise among these smaller groups. Sometimes, those who carefully adhere to one particular sect feel hatred or bigotry toward those of other sects, no matter how closely related their ideologies are.
Sectarianism is the result of different, though related, groups maintaining a strict division. The cult of Mormonism, for example, contains several sects. The two main sects are the Church of Jesus Christ of Latter-day Saints and the Community of Christ. Other sects within the same church are the Church of Christ (Temple Lot), the Church of Jesus Christ, the Fundamentalist Church of Jesus Christ of Latter-day Saints, and, for a while, the Rigdonites.
Sectarianism can lead to violence at times. A couple famous examples are the Nationalists vs. the Unionists in Northern Ireland and the Sunni vs. Shia Muslims. Usually, conflict is based on a belief that the ideologies of opposing sects cannot coexist peacefully without doing damage to the religion or political entity as a whole.
Within genuine Christianity, there are sects and denominations aplenty. Sectarianism within Christianity does not often lead to physical violence, thankfully. But it can still cause misunderstanding and unnecessary division. Yes, we must contend for the faith and defend the gospel from those who would pervert the grace of God (Jude 1:3–4). Truth is, by definition, exclusive of falsehood; we must separate from heresy. But much conflict within the church is unnecessary and unbiblical (2 Timothy 2:23; Ephesians 4:1–8). Spiritual maturity is associated with unity, which is only possible as the people of God gather around the Word and agree on it (Ephesians 4:13–16). Sectarianism within Christianity often centers on differing applications of truth and differing traditions, rather than differing facts.
Jesus had to deal with a sectarian attitude among His disciples. John came to Jesus one day and said, “Teacher . . . we saw someone driving out demons in your name and we told him to stop, because he was not one of us” (Mark 9:38). Rather than compliment John for his zeal, Jesus rebukes him for his sectarianism: “Do not stop him. . . . For no one who does a miracle in my name can in the next moment say anything bad about me, for whoever is not against us is for us. Truly I tell you, anyone who gives you a cup of water in my name because you belong to the Messiah will certainly not lose their reward” (Mark 9:39–41).
From this incident, we learn several things. First, the Lord can use people other than those involved in our “sect.” John and the other disciples had assumed that, because the unnamed exorcist was not one of the Twelve, he was therefore not a true follower of Christ. Jesus sets the disciples straight, telling them they had no right to forbid the man from his activity. Further, we learn that the Lord has works in progress that we know nothing about. He doesn’t need to get our approval before He chooses to act; if He desires to use someone not associated with our organization, then that’s His business. Sectarianism is barred by the words “whoever is not against us is for us.”
The important facts about the exorcist in Mark 9 are that he was using his gift in the name of the Lord and that Jesus sanctioned him. We cannot assume that other Christians are not “really” serving the Lord simply because they don’t run in our circles. Any service in Christ’s name, even just supplying a cup of water to a disciple, will be rewarded. We should allow the Giver of all good gifts to hand out the rewards as He sees fit. We can avoid sectarianism by allowing God’s Spirit to work in us, for peace is a fruit of the Spirit of Christ (Galatians 5:22; Colossians 3:15).