How do we know that Christ prayed for unity among believers?

In John 17:20-21, Jesus explicitly mentions His prayer for those who will believe in Him to be one, just as He and the Father are one. This prayer highlights the importance of unity among believers as it reflects the nature of God. The call for unity is deeply rooted in the mission of the Church; it serves as a witness to the world about Christ's redemptive power and truth. Furthermore, this unity is not a mere suggestion but is emphasized in the continual prayers of Jesus, reinforcing the necessity for believers to maintain harmony with one another for the sake of the Gospel.