Everyone is called to pursue sainthood through living the Works of Mercy, though it is not for the weak of heart, Pope Francis told more than 60,000 young altar servers in St. Peter's Square Tuesday.

"It is true, it is not easy, but remember – I will say it again – the way of holiness is not for the lazy," the pope said July 31.

"Do you all know the Works of Mercy? It's important!" he said. "To learn the Works of Mercy it is not necessary to go to university or to receive a degree, all can learn."

In a question and answer session, Pope Francis advised the pilgrims to "know and love the Lord Jesus more and more," encountering him in prayer, at Mass, through reading Scripture, in the poor.

"Even now, as young people, you can be apostles, capable of drawing others to Jesus. This will happen if you are full of enthusiasm for him, if you have encountered him, if you have come to know him personally, and been yourselves 'won over' by him," he said.

The pope also encouraged them to be friends with everyone, "no strings attached," in order to be a "ray of Jesus' light," because, he said, everyone needs friends who give a good example and who give without expecting anything in return.

"There is no need for lots of words; more important are your actions, your closeness, your desire to serve, gazing before the Most Blessed Sacrament," he said. "In this way, you will also help others to see how beautiful the community of believers is, because the Lord dwells in its midst."

Pope Francis met with the more than 60,000 youth, ages 13-23, during the 12th international pilgrimage of altar boys and girls, run by the International Union of Altar Servers.

Hailing from 19 countries, with over 80 percent from Germany, this year's pilgrimage was the first to include a group of altar servers from the United States. A group of 90 altar boys and girls from a Vietnamese parish in the US joined the week-long event.

The theme of the pilgrimage was "Seek peace and pursue it!" In the Q-and-A, the pope answered five questions from altar servers, including one about peace.

Peace, he said, is a gift from the Lord. "At the end of Mass, we are sent forth with the words: 'Go in peace.' Concrete commitment to peace is proof of the fact that we are truly Christ's disciples."

Noting that commitment to peace begins with small things, he pointed to the example of a quarrel and told the young people to ask themselves, "What would Jesus do in my place?"

"If we can do this, if we really put it into practice, we will bring Christ's peace to our everyday lives."

Francis also spoke about sanctity, affirming that it takes effort to do good and to become saints, but that the way to advance in holiness is simple: to love God and neighbor.

"We have only to start asking ourselves: 'What can I do today to meet the needs of my neighbor?' It makes no difference whether it is a friend or a stranger, a countryman or a foreigner. Believe me, by doing this, you can become real saints, men and women who transform the world by living the love of Christ," he said.

After the questions and answers, Pope Francis celebrated Vespers with the pilgrims. In his brief homily, the pope told the altar servers to, as St. Paul says, "Do everything for the glory of God."

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"To give glory to God in everything we do: that is the ultimate criterion for all our words and actions," he said. "It sums up what it means to be a friend of Jesus. It shows us the way when we are unsure about the right thing to do. It helps us recognize God's voice speaking in the depths of our conscience so that we can know his will."

Though the mission may be difficult, it can be carried out by imitating Christ and the saints, he said, pointing to St. Ignatius of Loyola, whose feast day is July 31.

"Maybe you are wondering: 'Can I do this? Isn't it too much for me?' Certainly, it is a great mission, but it is not impossible," the pope said. "So let us imitate the saints. Let everything we do be for God's glory and the salvation of our brothers and sisters."

And remember, he concluded: "In this way of holiness, there is no place for lazy young people!"