Be one: For believers, becoming one with one another is an outgrowth of the union they enjoy with Jesus himself, a union modeled on the oneness of the Father and the Son.
May they also be in Us: Through the Holy Spirit's power, believers experience a profound and intimate union with the Father and the Son, leading to transformation (14:20, 23; 1 John 4:13).
Disciples of Jesus represent him, so their right actions and relationships with each other reflect the credibility of Christ in the world. When there is disunity, infighting, and intolerance, their testimony to the world is unconvincing. When people observe the community of believers, they know that it represents Jesus; a unified, loving community convinces the world to believe (John 13:35; 1 John 3:11).