Ephesians 4:1 I therefore, the prisoner of the Lord, beseech you that ye walk worthy of the vocation wherewith ye are called,
4:2 with all lowliness and meekness, with longsuffering, forbearing one another in
4:3 endeavoring to keep the unity of the Spirit in the bond of peace.
4:4 There is one body, and one Spirit, even as ye are called in one hope of your calling;

Jesus taught the importance of unity and love in his followers. He considered it so important that in one of his last recorded prayers to God (John 17:21-23), he expressed the unity that he had with God and prayed for that same unity to be among his followers.

Unity is based on individuals drawing together as one over a common belief or goal. Jesus made it clear to his followers that their unifying factor was to be him (John 14:6). He also provided them with an example of how he expected them to treat each other with love, support and servitude when, in one of the last acts of his life, he washed their feet (John 13:1-17).

The Apostle Paul carried on the work of spreading the gospel message and helping to found and teach the early Christian churches after Jesus’ death and resurrection. The goal of being faithful to God was Paul’s main purpose in life (Philippians 3:13-14). Even in the early days of the Christian churches, he saw false teachers, pagan beliefs, worldly ambitions and conflicts among church members begin to creep into their fellowships. In Ephesians 4:1, Paul reminds his brethren of that one purpose in life, “the vocation wherewith ye are called”—to sacrifice the goals of this world in favor of serving God with all one’s heart, just as Jesus did. This common goal was meant to unite the members of the early churches and help keep them from adopting the negative influences around them. All who have made a consecration of their lives to God, then and now, share in God’s power and influence, the holy spirit (John 14:26). That spirit, if received into willing hearts and minds, will develop characters that recognize the same influence of the spirit in others (“the unity of the spirit”) and that reflect the teachings of love and peace with one’s brethren (“the bond of peace”) that Jesus exemplified and taught.

Additional Resource:
Christian Question Podcast
Episode #1077: “We are Christians, But Are We Unified?”
Examining the concept of Christian unity against the proliferation of branches of Christianity
CQ Rewind Show Notes