For you are still carnal. For where there are envy, strife, and divisions among you, are you not carnal and behaving like mere men? 1 Corinthians 3:3
Some things in life don’t go together: oil and water, nuts and chewing gum, love and hate, and criticism and unity. Constructive criticism can lead to greater unity. But when the criticism is motivated by selfishness, envy, or anger, it can never lead to unity.
What can lead to unity? Service. Take the church at Corinth for example. The apostle Paul wrote stern rebukes to the church about their lack of unity. Men like Paul and Apollos came among them as servants (1 Corinthians 3:5) to build up a church characterized by unity. But the immature Corinthian believers ignored the model of servant leadership and created cliques in the church based on “envy, strife, and divisions.” The other model of service they could have followed was that of Christ who came into the world to serve, not to be served (Mark 10:45; Philippians 2:7). Servants look first to the interests of others rather than their own interests (Philippians 2:4), and unity results.
Unity comes when individual Christians submit their will and agenda to the Lordship of Jesus Christ—it’s the best way to begin every day.
In necessary things, unity; in doubtful things, liberty; in all things, charity. Richard Baxter
1 Corinthians 3 – Part One – Children of God