Vatican City, Sep 3, 2016 / 04:22 am (CNA/EWTN News).- Mercy is not an abstract idea, but is rather expressed in concrete actions of love toward the poor and needy, who in their daily lives walk the same path of Calvary that Jesus did, Pope Francis has said.

“Love is the highest expression of life; it allows us to exist!” the Pope said Sept. 3, speaking to an audience of workers and volunteers of mercy present for a special Jubilee in their honor.

When confronted with this “truth of the faith,” the Church, he said, “cannot look away and turn her back on the many forms of poverty that cry out for mercy… Calvary is always real; it has not disappeared at all, nor does it remain with us merely as a nice painting in our churches.”

To walk by and ignore the man dying on the side of the road, he said, “is a serious sin! It’s a modern sin, it’s the sin of today!”

“We Christians cannot allow ourselves to be like this,” Francis said, adding that “it is not worthy of the Church nor of any Christian to pass by on the other side and to pretend to have a clean conscience simply because we have said our prayers!”

The culmination of love and compassion achieved by Christ with his death on the cross “still speaks to us today and spurs us on to offer ever new signs of mercy,” the Pope continued, adding reiterating what he has said on several occasions: “the mercy of God is not some beautiful idea, but rather a concrete action.”

Pope Francis’ catechesis was given as part of a special Sept. 2-4 Jubilee for Workers and Volunteers of Mercy, which is part of his wider Holy Year of Mercy and coincides with the canonization of Bl. Mother Teresa of Calcutta.

The jubilee will culminate Sunday, Sept. 4, with the canonization Mass for Bl. Mother Teresa of Calcutta, considered one of the greatest witnesses of mercy in our time.

Before Pope Francis spoke during the catechesis session, he heard the testimony of an Italian man who experienced mercy from the chaplains and volunteers while serving time in prison. He also listened to the story of Sr. Sally, a Missionary of Charity sister who survived the bloody March 4 attack on their convent in Yemen that left 16 dead, including four sisters.

In his speech, the Pope focused on the scripture passage for the event, in which St. Paul in his Letter to the Corinthians speaks about love, which “never ends.”

This teaching, he said, “must be for us an unshakable certainty; the love of God will never diminish in our lives or in human history. It is a love which remains forever youthful, active, dynamic and which has an attraction beyond all telling.”

God’s love comes toward us like “a swelling river that engulfs us without overwhelming us,” he said, adding that the more we allow ourselves to be taken in by this love, the more our lives will be renewed.

Francis stressed that the love St. Paul describes is not an “abstract of vague” idea, but is something seen, touched and experienced firsthand.

Jesus is “the greatest and most expressive form of this love,” he said, explaining that the Lord’s entire life and being “are nothing other than the concrete revelation of the Father’s love, reaching its highest expression on the Cross.”

Addressing the participants directly, Pope Francis said they as volunteers and workers of mercy “are among the most precious things the Church has.”

By working silently every day in service to others, “(you) give shape and visibility to mercy. You express one of the most noble desires of the human heart, making a suffering person feel loved.”

He told the workers and volunteers to never forget that they “touch the flesh of Christ” with their own hands daily in their work and encouraged them to be generous in solidarity.

“The world stands in need of concrete signs of solidarity, especially as it is faced with the temptation to indifference,” he said, noting how true solidarity requires people who are ready to “defy such individualism, which is the tendency to think only of oneself and to ignore the brother or sister in need.”

In addition to going beyond individualism and indifference, Francis urged the volunteers to “always (be) happy and full of joy” in their service, but cautioned them “never presume to think that you are superior to others.”

“Instead, let your work of mercy be a humble and eloquent continuation of Jesus’ presence who continues to bend down to our level to take care of the ones who suffer.”

Pope Francis concluded his address noting how he will proclaim Mother Teresa a saint tomorrow, Sept. 4, adding “She deserves it!”

Mother Teresa’s witness to mercy, he said, “will join the vast array of men and women who, by their holiness of life, have made the love of Christ visible.”

“Let us also imitate their example, as we ask to be humble instruments in God’s hands in order to alleviate the world’s sufferings, and to share the joy and hope of the resurrection,” he said, and closed by leading pilgrims in a moment of silent prayer for all those who are suffering, for the indifferent, and for the volunteer and workers “who go out to encounter the flesh of Christ.”