Christian unity in faith and love is God’s will because Jesus prayed that all who believe in Him should be one, in order that the whole world would know that His Father sent Him.
The night before He suffered His Passion and death, Jesus prayed for Christian unity. “I do not pray for these only, but also for those who believe in me through their word, that they may all be one; even as thou, Father, art in me, and I in thee, that they also may be in us, so that the world may believe that thou hast sent me” (John 17:20-21).
Seeing how the early Christians loved and honored one another, the pagans came to believe that the Christian God was the true God.
Jesus said, “I am the good shepherd; I know my own and my own know me, as the Father knows me and I know the Father; and I lay down my life for the sheep. And I have other sheep, that are not of this fold; I must bring them also, and they will heed my voice. So there shall be one flock, one shepherd” (John 10:14-16).
Jesus founded but one Church, that which is built upon Peter the Rock. Moreover, Jesus brought the same Good News to all men, and called all to the same new life. His Church subsists in the Catholic Church, which is the world-wide community of the followers of Jesus united around the Pope.