Pope Francis delivered a video message to a Christian unity celebration in Phoenix.

While Christians may think of themselves as divided into different churches and denominations, the devil actually sees that they are one in their faith in Jesus, Pope Francis said in a video message to a Christian unity celebration in Phoenix.

“Division is the work of the ‘Father of Lies,’ ‘the Father of Discord,’ who does everything possible to keep us divided,” the Pope said on Saturday in the message to the gathering sponsored by the John 17 Movement.

“I feel like saying something that may sound controversial, or even heretical, perhaps,” he said in the video. “But there is someone who ‘knows’ that, despite our differences, we are one. It is he who is persecuting us. It is he who is persecuting Christians today, he who is anointing us with (the blood of) martyrdom.”

The devil, he said, “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.”

The John 17 Movement — named after the Bible passage in which Jesus prays for the unity of his disciples — includes evangelicals and Catholics. One of the participants at the Phoenix meeting was Giovanni Traettino, a Pentecostal pastor from southern Italy whom the pope has known since his days in Buenos Aires. The Pope visited Traettino’s church last summer.

The Pope promised Traettino and all those gathered in Phoenix that he would spend the day praying with them for the grace of unity, “the unity that is budding among us is that unity which begins under the seal of the one baptism we have all received.”

In the video produced by the Vatican television centre, Pope Francis told the group that “division is a wound in the body of the church of Christ. And we do not want this wound to remain open.”

Christians, he said, must seek unity together, they must pray for one another and they must work together to assist the poor and vulnerable.

While the Catholic and mainline churches have been engaged in high-level ecumenical dialogues for 50 years, Pope Francis told the Phoenix meeting, “I am convinced it won’t be theologians who bring about unity among us.”

The work of theologians is essential for understanding, he said, “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,” he said, and Christians must open their hearts to the Spirit’s gifts with “prayer, friendship, closeness and reflection.”