If I say “Calcutta,” the image that probably comes to mind is that of a small woman in a sari edged with three blue stripes.

This summer we were there for three weeks with the group organized by the Youth section of Regnum Christi in Ronda (Madrid). We were a mission team of 26 university students and young professionals between the ages of 23 and 30, coming from Madrid and other Spanish cities, as well as from Mexico and Argentina. We were accompanied by Fr. Nicolás Núñez, L.C., to serve alongside the Missionaries of Charity Sisters and care for our poorest brothers and sisters in Mother Teresa’s homes.

On the first day we walked along part of the railway tracks, where we met people who live—or, rather, survive—there. I had never seen or touched such poverty. And yet, in Mother Teresa’s time the situation was even more extreme. It felt like experiencing the bite of life’s cruelty. Like when, on a city street, we came across a young woman who had just given birth on the sidewalk…

We were in a suburban area where so many live and sleep on the street, wash in the street. Where almost everything is dirty, where the smell is intense, where the humid heat envelops you all day long. Where there are mosquitoes, rats, and an astonishing number of stray dogs. A place where it would seem that beauty does not dwell.

Touching this reality helped us better understand the meaning and value of Mother Teresa’s work and of our volunteer service. Because thanks to that woman from Albania who heard Christ’s agonizing cry on the cross—“I thirst”—today there are between two and three thousand people in Calcutta whose lives have been transformed. People who once were treated as the refuse of society now have a home, and are looked at and treated as what they truly are: human beings, brothers and sisters in need.

Mother Teresa used to say that “peace begins with a smile,” and that it is not about doing extraordinary things, but about “doing small things with great love.” And we saw this in the Nirmal Hriday homes—“pure heart” in Bengali—where life is simple but finally dignified.

Each of us was assigned to a different house: homes for the poorest of the poor, mostly people with physical or mental disabilities. There we offered our hands and our hearts: in the laundry, in cleaning, in physiotherapy, in serving meals, or simply by being with them.

But how can we give love if we have not first received it? That is why each day began with the Eucharist and ended with Eucharistic adoration at the Mother House, the headquarters of the Missionaries of Charity, where Mother Teresa lived and worked until her death. It was there that we received strength, joy, and the love of God’s heart.

The encounters with some of the Sisters were also very meaningful, such as Sister María Ruth, from Madrid, a former Mater student, in love with Christ and passionate in her service to the poorest. She shared with us how the Eucharist and the rosary sustain her life.

Our group has now returned. We did not change Calcutta… but Calcutta changed us. It has remained within us. We left grateful. The Sisters highlighted the good spirit and dedication of these young volunteers, many of whom already wish to return.