Young Catholics can be a force for joy and peace, Pope Francis told an audience with Catholic Action on Monday.

"Proclaiming to all the love and tenderness of Jesus, you become apostles of the joy of the Gospel. And joy is contagious," he told members of Catholic Action who had gathered in Vatican City's Consistory Hall to wish the pontiff a Merry Christmas.

Reflecting on the Nativity of Jesus Christ, he said: "The birth of Jesus is announced as a great joy, originating from the discovery that God loves us and, through the birth of Jesus, made Himself close to us to save us. We are beloved by God. What a wonderful thing!"

"When we are a little sad, when it seems that everything is going wrong, when a friend disappoints us – or rather, when we disappoint ourselves – let us think 'God loves me', 'God never abandons me'," the Pope said Dec. 19.

He said that God is always faithful and never ceases to love us even when we stray.

"This is why in the heart of a Christian there is always joy," the Pope said. "And joy multiplies when shared!"

Citing Catholic Action's motto for the year, "Surrounded by Joy," he encouraged those gathered to surround with joy those they meet each day.

Pope Francis also gave the youth a homework assignment: to share joy with their grandparents.

"Speak often with your grandparents. They too have this contagious joy," he said. "Ask them many things, listen to them: they have the memory of history, the experience of life, and for this reason it will be a great gift that will help you on your path."

"They too need to listen to you, to understand your aspirations, your hopes. … The elderly have the wisdom of life," he added.

The Pope told Catholic Action that their commitment to peace is also contagious. He cited a Catholic Action initiative in a disadvantaged neighborhood of Naples, and asked God to bless it.

Pope Francis wished a merry Christmas to all of Catholic Action, especially its collaborators who are educators, assistants and national leaders. The Pope asked them to pray for him.

He also encouraged prayers for Bishop Mansueto Bianchi, a general ecclesiastical assistant for Catholic Action who passed away in August 2016.