In a world marked by suffering and fierce persecution – especially of Christians – now "is the time for mercy," Pope Francis said, speaking at the vigil for the Feast of Divine Mercy.

Reflecting on the ongoing persecution faced by Christians, the Pope said, "our prayer is all the more intense and becomes a cry for help to the Father, who is rich in mercy, that he may sustain the faith of our many brothers and sisters who are in pain."

For our part, we are to seek the grace of "conversion of our own hearts," whereby we are moved "from indifference to compassion," he added.

The pontiff made these remarks during his homily for Evening Vespers in St. Peter's Basilica, minutes after a public proclamation of the Jubilee for Mercy in front of the Holy Door.

The Jubilee is an Extraordinary Holy Year that will open this year on Dec. 8 – the Solemnity of the Immaculate Conception – and will close Nov. 20, 2016 with the Solemnity of Our Lord Jesus Christ, King of the Universe.

The Pope first announced the Year of Mercy on March 13, the second anniversary of his pontifical election, during a Lenten penitential liturgy in St. Peter's Basilica.

Mercy is a theme that is dear to Francis, and is the central topic of his episcopal motto "miserando atque eligendo," which he chose when ordained a bishop in 1992.

Speaking the evening before the Feast of Divine Mercy, which falls on the first Sunday after Easter, Pope Francis recalled Jesus' words to his disciples, "Peace be with you!"

During the Easter season, he said, this concept of peace "remains the desire of so many people who suffer unprecedented violence of discrimination and death simply because they bear the name 'Christian'."

Regardless of life's difficulties and sufferings, the pontiff said – citing St. Paul – the hope of salvation won for us the mystery of Jesus' death and resurrection "continues to grow."

"The mercy of God is poured out upon us, making us just and giving us peace," he said. "This is a time for the Church to rediscover the meaning of the mission entrusted to her by the Lord on the day of Easter: to be a sign and an instrument of the Father's mercy."

Pope Francis explained that he declared this Jubilee of mercy because we are living at a "time of great historical change" which calls the Church "to offer more evident signs of God's presence and closeness."

This period in history is a time where the faithful "need to be vigilant and to reawaken in ourselves the capacity to see what is essential," he said.

"This is the time for mercy."

The aim of Jubilee Year of Mercy is to encourage the faithful to "welcome the numerous signs of the tenderness which God offers to the whole world," the Pope continued.

These signs of God's tenderness are especially offered to the suffering, the alone, the abandoned, and those "without hope of being pardoned or feeling the Father's love."

"It is the favourable time to heal wounds," he stressed, "a time not to be weary of meeting all those who are waiting to see and to touch with their hands the signs of the closeness of God, a time to offer everyone the way of forgiveness and reconciliation."

Pope Francis concluded his short address by calling on Mary to help the faithful "comprehend the task to which we have been called" during this Holy Year of Mercy, helping to experience the year "as faithful and fruitful witnesses of Christ."