The Lord has called all who would follow Him into the “unity of the Spirit in the bond of peace” (Ephesians 4:3) to “speak the same thing” (1 Corinthians 1:10) as our “common confession” (1 Timothy 3:16 NAS): the gospel of Christ in truth; the only hope for a lost and dying world.
The Bible teaches Christians to have unity in belief and doctrine. On the one hand, Paul (1 Corinthians 1:10) appeals for utter agreement in “mind” (i.e. understanding) and “judgment” (rendered “opinion” in several translations), and Jesus (John 17:17ff) petitions the Father to help us be sanctified in the truth, and united to the same degree the Father and He are united. That is complete unity! Therefore, we ought to always think of the unity of all believers in all aspects of spirituality as a genuine goal. If it is not reachable previous to the Lord’s return it is not because the Lord has asked for the impossible, but because people are always going to be at different levels in their growth. Jesus will complete the unity of all true believers at his return, but until then we must constantly pray and study and then teach and correct all men until we attain that unity the Lord desires (Ephesians 4:13). This must be done with love and great patience (Ephesians 4:15; 2 Timothy 2:24-25, 4:2).
On the other hand, with all love, having exhausted every patient effort to settle the dispute otherwise, when a brother or sister stubbornly persists in spreading false doctrine or behaving in a way that is inconsistent with Christian belief, he or she must be expelled from the congregation (Romans 16:17-18; 1Corinthians 5:11-13; 2Thessalonians 3:14-15; Titus 3:10-11). Such an act of “church discipline” is born of love, desiring the repentance of the sinful one, and the protection of the weak. Let every Christian beware of reacting against a disagreeing brother hastily, or in anger (Galatians 5:20; Ephesians 4:26, 31; Colossians 3:8; James 1:19-20), remember to handle disagreements as discreetly as possible for as long as possible (Proverbs 3:21, 5:2, 8:12), and follow the Lord’s proper order (Matthew 18:15-17). While we can always patiently endure the misunderstandings of those less mature in the faith than ourselves (as we seek the patience of those more mature than we), we cannot have unity with bold, impenitent proclaimers and practitioners of that which is against Christian belief as revealed through Christ in the Scriptures. Remember, we are not trying to “be right,” or “win arguments” for pride’s sake, so always give the one with whom you may have a disagreement the space to consider the situation and change his mind with his dignity intact.
(Excerpt from That You May Grow Thereby, Vol.3, by Tim Mitchell and Joshua Pappas. Available from Gospel Advocate, Mars Hill, DeHoff, and 21st Century Christian Bookstores.)