Rom. 12:16 Live in harmony with each other. Don't try to act important, but enjoy the company of ordinary people. And don't think you know it all!
Churches seem to be the worst offenders of this verse. Some church bodies are so into their own world that they will not fellowship with anyone else. They think that to do so would put their doctrinal position into jeopardy. They fear that they might think differently about things and no longer stand on solid Biblical ground. Thus, they choose not to fellowship with other church bodies or work with them for the advancement of the Gospel.
Living in harmony with one another is often difficult and not done. Rather than work through issues, there is the tendency to just break fellowship with one another. It happens a lot within the church. One may sit next to someone in church and even serve alongside of them, but be out of fellowship with them. Such living is sin.
Some try to act important in the church. They get the idea because of what they do or have accomplished in life that they are better than others. In God's family, no one is any more important than anyone else. Period. No one is worthy of being exalted to a higher status than anyone else. Instead, we are to enjoy each other's fellowship. Church life would be so much more enjoyable for everyone if we would do this.
Protect your soul. Don't think you know it all; you don't. No matter how much you may have learned about life, the Scriptures, how to apply them, and people, you don't know it all. We are all in the learning process. There is so much more to learn than what you think you know. Don't let your knowledge puff you up; it is sin. Humbly use what you do know for the honor and glory of Christ.