One passage that lays bare the heart behind divisiveness is Romans 16:17–18:
I appeal to you, brothers, to watch out for those who cause divisions and create obstacles contrary to the doctrine that you have been taught; avoid them. For such persons do not serve our Lord Christ, but their own appetites, and by smooth talk and flattery they deceive the hearts of the naive.
A person is being divisive as he relates to others by making distinctions on issues that God does not. A divisive person insists on his own categories of division, often baptizing them with biblical language. But Paul’s language makes clear that divisive people serve “their own appetites” despite their claims for a holy cause. They long to be in a community that feels clean and safe for those desires to go unchallenged. So they prefer clean lines of demarcation where the Bible does not draw them.
A divisive person demands uniformity where God does not, which destabilizes unity in Jesus Christ. The Apostle Paul insisted that lesser loyalties will always push against the greatest loyalty to Christ; Christians must be on guard against this in their own hearts (1 Cor. 1:12). To enforce this uniformity, they will use ugly weapons: sowing suspicion of others, exaggerating others’ faults, misrepresenting others’ positions, flexing the muscles of their own influence against others, or even slandering. God finds no pleasure in those who sow discord in this way (Prov. 6:16–19). If we are ever going to be actual experts in what pleases and displeases the Lord, we’d better take that seriously.