Pope Francis on Monday marked the conclusion of the Week for Christian Unity, saying all Christians are united by the call to conversion and the mission to proclaim the Gospel.  

“Beyond the differences that still separate us, we joyfully recognize that, at the origin of the Christian life there is always a call whose author is God,” the Pope during his Jan. 25 homily at Vespers for the Feast of the Conversion of St. Paul.

“Conversion means let the Lord live and work in us,” the Roman Pontiff said. “For this reason, when Christians of different churches together to the Word of God listen and try to put it into practice, they accomplish truly important steps towards unity.”

“The mission of the whole people of God is to proclaim the wonderful deeds of the Lord, above all the Paschal mystery of Christ, through whom we have passed from the darkness of sin and death, the glory of his life, the new and eternal.”

The annual Week for Christian Unity runs Jan. 18-25, and is organized by the Pontifical Council for the Promotion of Christian Unity, the Commission on Faith, and the Order of the World Council of Churches.

This year’s theme, “Called to proclaim the mighty acts of the Lord,” is taken from chapter two of the First Book of Peter, and was chosen by a group from Latvia, which is home to a strong presence of Catholic, Orthodox, and Protestant Christians.

Presiding over the event at Rome's Basilica of Saint Paul Outside the Walls, Pope Francis recounted in his homily the story of Paul (previously known as Saul), a Jew who, before his conversion, had persecuted the early Christians. As the account goes, Saul was thrown from his horses and blinded while en route to Damascus. Hearing a voice say: "Saul, Saul, why dost thou persecute me?” Asking who was speaking, Saul heard in reply: "Jesus of Nazareth, whom thou persecute.”

“In that moment, in fact, Paul understood that, between the eternally living Christ and his followers, there is a real and transcendent union: Jesus lives and is present in them, and they live in him,” the Pope said.

“The vocation to be an apostle is based not the human merit of Paul, who considered himself to be 'lowly' and 'unworthy', but on the infinite goodness of God, who chose him and entrusted him with the ministry.”

The Pope spoke on Paul's gratitude for the mercy which enabled him to serve God, despite having formerly been a “blasphemer” and “persecutor.”

“The abundant mercy of God is the only reason on which is established Paul's ministry and at the same time, it is what the Apostle must announce to all.”

Pope Francis observed how Paul's experience was like that of the early Christian communities.

“For these early Christians, like for all of us baptized today, it is a source of comfort and constant wonder to know we have been selected to be part of God's the plan for salvation, carried out in Jesus Christ and in the Church.”

“We draw here the mystery of God's mercy and choice: the Father loves everyone and wants to save everyone, and for this it is called by some 'conquering' with his grace, because through them his love reaches everyone.”

Reflecting on the Week for Christian Unity, Pope Francis noted how all believers in Christ are called to proclaim his wondrous works.

He spoke of moving toward “full visible communion among Christians,” not only in becoming closer, but in being converted by the Lord's grace, and the call to be his disciples.

We are united not only by the same call but by the same mission, the Pope said: “to proclaim to all the wonderful works of God.”

“As we journey towards full communion between us, we can already develop multiple forms of collaboration in order to promote the spread of the Gospel,” he said. “And walking and working together, we realize that we are already united in the name of the Lord.”

Reflecting on the current Jubilee Year of Mercy,  Pope Francis said the authentic search for Christian unity depends on being fully entrusted to the Father's mercy.

“First of all we ask forgiveness for the sin of our divisions, which are an open wound in the Body of Christ,” he said.

Speaking as Bishop of Rome and leader of the Catholic Church, Pope Francis asked for mercy and forgiveness on account of the “non-evangelical” behavior on the part of Catholics toward their separated brethren.

He also called on Catholics to forgive wrongs done to them by other Christians.

“We can not undo what has been, but we will not allow the weight of past sins continue to pollute our relationships. The mercy of God renewed our relationships.”

Pope Francis welcomed the representatives of all the various Churches and ecclesial communities present at the gathering.

“With them we passed through the Holy Door of this Basilica to remember that the only door which leads us to salvation is Jesus Christ our Lord, the merciful face of the Father.”

“Unity is the gift of the mercy of God the Father,” the Pope said.

Concluding his homily he indicated the tomb of St. Paul, who is buried under the main altar of the basilica.

“Here before the tomb of St. Paul, apostle and martyr, kept in this splendid basilica, we feel that our humble request is supported by the intercession of the multitude of Christian martyrs of yesterday and today.”

“They have responded generously to the call of the Lord, they gave faithful witness, with their lives, the wonderful works that God has done for us, and experience already in full communion with the presence of God the Father.”

“Sustained by their example — as we see, for instance, in the ecumenism of blood — and comforted by their intercession, we turn to God our humble prayer.”