John 17:21

That they all may be one (Greek: ἵνα πάντες ἓν ὦσιν, ina pantes hen ōsin) is a phrase derived from a verse in the Farewell Discourse in the Gospel of John (17:21) which says:

that they may all be one. As you, Father, are in me and I am in you, may they also be in us, so that the world may believe that you have sent me.

The phrase forms the basis of several ecumenical movements and united and uniting denominational traditions. It is also a common sermon topic on church unity.

The phrase is the official motto of the Church of South India. The Latin version, Ut Omnes Unum Sint, is the motto of the World Student Christian Federation, the University of Mainz, the United Church of Canada and the YMCA. The United Church of Christ has the same motto except for a change in the place of one word: "That they may all be one."

The phrase is also the motto of the Graymoor Friars (the Society of the Atonement). They have used this phrase for over 100 years to describe the apostolate of the order. The Society of The Atonement started the worldwide observance of "The Church Unity Octave." The work of this Roman Catholic, Franciscan, religious order is Ecumenism.

Pope John Paul II published an encyclical under the Vulgate form this title, Ut Unum Sint.

It is also one of two mottoes of Spalding Grammar School in Lincolnshire, England. It is the motto of Achimota School located in Accra, Ghana and both Strathmore School and Strathmore University in Nairobi, Kenya. St. Paul's School in Rourkela Orissa, India also bears this motto on its Badge. It is also the motto of the Presbyterian Church of Ghana.

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