Unity is an important trait for God’s people to possess because unity is the trait that Jesus said would declare His deity. In John 17:20-21, Jesus prayed for His disciples to be united with each other and with God, and the reason He prayed for this is “so that the world may believe that you have sent me.” So, while love may be the trait that declares to the world that we our followers of Jesus, unity is the trait that declares to the world that Jesus is the Christ. So, what does Christian unity entail?
I therefore, a prisoner for the Lord, urge you to walk in a manner worthy of the calling to which you have been called, 2 with all humility and gentleness, with patience, bearing with one another in love, 3 eager to maintain the unity of the Spirit in the bond of peace. 4 There is one body and one Spirit—just as you were called to the one hope that belongs to your call— 5 one Lord, one faith, one baptism, 6 one God and Father of all, who is over all and through all and in all.7 But grace was given to each one of us according to the measure of Christ’s gift.8 Therefore it says,
“When he ascended on high he led a host of captives,
and he gave gifts to men.”9 (In saying, “He ascended,” what does it mean but that he had also descended into the lower regions, the earth? 10 He who descended is the one who also ascended far above all the heavens, that he might fill all things.) 11 And he gave the apostles, the prophets, the evangelists, the shepherds and teachers, 12 to equip the saints for the work of ministry, for building up the body of Christ, 13 until we all attain to the unity of the faith and of the knowledge of the Son of God, to mature manhood, to the measure of the stature of the fullness of Christ, 14 so that we may no longer be children, tossed to and fro by the waves and carried about by every wind of doctrine, by human cunning, by craftiness in deceitful schemes.15 Rather, speaking the truth in love, we are to grow up in every way into him who is the head, into Christ, 16 from whom the whole body, joined and held together by every joint with which it is equipped, when each part is working properly, makes the body grow so that it builds itself up in love.”
Ephesians 4:1-16