“It’s an ugly thing that we Christians are divided,” said Pope Francis Sunday. “Jesus wants us united in one single body,” he said.

In his weekly Angelus message, the Pope spoke of the week of prayer for Christian unity, which ends this evening with a prayer service at the basilica of Saint Paul Outside the Walls in Rome.

“Our sins, our history have divided us,” Francis said. “We need to pray so the Holy Spirit will unite us once again.”

As he has done on other occasions, Pope Francis pointed to the action of Satan as the cause of the rifts among Christians.

“The devil,” said Francis, “is the father of divisions. He always divides, makes war and does so much evil.”

The Pope said that it is Jesus himself who “thirsts” for the unity of all Christians. “God thirsts for us,” he said, and in the heart of Christ “human and divine thirst meet.” The desire for the “unity of his disciples is part of this thirst,” he said, expressed in Christ’s prayer to the Father: “May they all be one.”

“Let us keep praying and committing ourselves for the full union of Christ’s disciples,” Francis said, “in the certainty that He is by our side and sustains us with the power of his Spirit who brings us toward that goal.”

After the prayer of the Angelus the Pope also expressed his growing concern for the conflict in the Ukraine, promising his prayers and begging for a cease to the violence and a return to dialogue.

“I am following with deep concern the escalation of the fighting in eastern Ukraine,” Francis said, “which continues to cause many casualties among the civilian population.”

“As I assure you of my prayers for all who suffer, I renew a heartfelt appeal for a resumed dialogue and an end to all hostilities,” he said.

Follow Thomas D. Williams on Twitter @tdwilliamsrome