VATICAN CITY (CNS) -- Christians should make a practice each night of identifying signs of hope, even small ones, that came their way during the day, Pope Francis wrote.

Living the virtue of Christian hope means "knowing how to discern, everywhere, evidence of hope, the breaking through of the possible into the impossible, of grace where it would seem that sin has eroded all trust," the pope said in the introduction to the book, "Hope Is a Light in the Night."

In preparation for the Holy Year 2025, Libreria Editrice Vaticana, the Vatican publishing house, prepared collections of Pope Francis' writing and preaching about Christian virtues with new introductions from the pope.

Vatican News Nov. 6 published the English-language translations of the pope's prefaces for the collection on hope and for one on faith, titled "Faith Is a Journey."

For the theme of the Holy Year, which he will open Dec. 24, Pope Francis chose "Pilgrims of Hope."

Reflecting on Christian hope, he wrote in the new book, is especially important "in times like the ones we are living, in which the Third World War being fought 'piecemeal' that is unfolding before our eyes can lead us to assume attitudes of gloomy discouragement and ill-concealed cynicism."

Christian hope is not optimism, he wrote. Rather, it is "waiting for something that has already been given to us: salvation in God's eternal and infinite love."

God's love and promise of salvation "gives flavor to our lives" and is "the hinge on which the world remains standing, despite all the wickedness and nefariousness caused by our sins as men and women."

"To hope, then, is to welcome this gift that God offers us every day," Pope Francis wrote. "To hope is to savor the wonder of being loved, sought, desired by a God who has not shut Himself away in His impenetrable heavens but has made Himself flesh and blood, history and days, to share our lot."

But hope also is a gift that requires a response of letting oneself "be molded" by God's love and sharing it with others, he wrote.

In encouraging people to go on the daily hunt for hope, the pope said the signs can be simple: "a smile from someone you didn't expect, an act of gratuitousness observed at school, a kind act encountered in the workplace, a gesture of help, even a small one."

"Let us train ourselves to recognize hope," he said. "We will then be able to marvel at how much good exists in the world. And our hearts will light up with hope. We will then be able to be beacons of the future for those around us."

The pope's introduction to the book on faith as a journey ties in closely with the practice of making a pilgrimage -- especially one on foot -- during the Holy Year.

"Walking is good for us: it connects us with what is happening around us, helps us discover the sounds, smells, and noises of the reality that surrounds us -- in other words, it brings us closer to the lives of others," he said.

A Holy Year pilgrimage also is a reminder that "faith is a pilgrimage and that we are pilgrims on this earth," the pope wrote. "We are not tourists or wanderers; we do not move aimlessly, existentially speaking. We are pilgrims," who take risks, put in effort and have a goal.

Reaching God is the goal "that continuously calls us to move forward because He is always greater than the idea we have of Him," the pope wrote. "But it is precisely this walking toward God that gives us the exhilarating certainty that He awaits us to give us His consolation and His grace."