Pope Francis has described the division between the different denominations of the Church as the work of the devil.
"Division is the work of the Father of Lies, the Father of Discord, who does everything possible to keep us divided," he said in a video message a 'Celebration of Christian Unity' event organised by the John 17 Movement in Phoenix, Arizona on Saturday. The movement is named after the biblical passage in which Jesus prays for his disciples "that they may be one as we are one".
The Pope said: "I feel like saying something that may sound controversial or even heretical, perhaps. But there is someone who 'knows' that, despite our differences, we are one...
"He knows that Christians are disciples of Christ, that they are one, that they are brothers! He doesn't care if they are Evangelicals or Orthodox, Lutherans, Catholics or Apostolic... he doesn't care! They are Christians."
He also said that the devil is responsible for the persecution of Christians around the world. "It is he who is persecuting Christians today, who is anointing us with (the blood of) martyrdom."
Francis added that Christians are united by their experience of persecution, saying: "we are living in an 'ecumenism of blood'."
He described division between Christians as "a wound in the body of the Church of Christ", adding that "we do not want this wound to remain open."
He assured the gathering of his prayers for them, and that he would join with them in praying for the grace of unity. And he called for Christians to work for unity: "to pray, to dialogue together, to shorten the distance between us, to strengthen our bonds of brotherhood."
The hope for unity in the Church relies on ordinary Christians, the Pontiff said, not on the work of theologians. "Theologians help us... but if we hope that theologians will agree with one another, we will reach unity the day after Judgement Day.
"The Holy Spirit brings about unity. Theologians are helpful, but most helpful is the goodwill of us all who are on this journey with our hearts open to the Holy Spirt!"
He ended his message by asking for their prayers, that he would be faithful to God's will for his ministry.
Among those attending the ecumenical event was Pentecostal pastor Giovanni Traettino, a friend of the Pope from his days in Buenos Aires, whom Francis visited at his church near Naples last year.
