With Christmas just eight days away, Pope Francis said three simple attitudes can help prepare us to welcome Jesus Christ.

"Saint Paul invites us to prepare for the coming of the Lord by assuming three attitudes: constant joy, persevering prayer and continual thanksgiving," the Pope said. "Joy, prayer and gratitude are three attitudes that prepare us to live Christmas in an authentic way."

Pope Francis' remarks to the crowds gathered in St. Peter's Square came ahead of the Angelus for Gaudete Sunday, the Third Sunday of Advent, which this year coincided with Pope Francis' 81st birthday, Vatican News reports.

He said the liturgy in recent Sundays has focused on how to be vigilant and how to prepare for the way of the Lord. For Gaudete Sunday, the liturgy invites Christians to joy.

The Pope cited St. Paul's First Letter to the Thessalonians, "always be happy."

"That is to say, always remain in joy, even when things do not go according to our desires," Francis explained. "Anxieties, difficulties and sufferings permeate our lives, and so many times the reality around us seems to be inhospitable and arid, like the desert in which the voice of John the Baptist resounded, as the Gospel of today recalls."

John the Baptist's voice in the desert reveals that Christian joy rests on "the certainty that the desert is inhabited."

This is Jesus, who in the words of the Prophet Isaiah comes "to bring the good news to the poor, to bind the wounds of broken hearts, to proclaim the freedom of slaves, the release of prisoners, to promulgate the year of grace of the Lord."

Jesus' mission in the world consists of "liberation from personal and social sin and the slavery that it produces."

"He came to earth to give back to men the dignity and freedom of the children of God, which only He can give," said Pope Francis.

Unceasing prayer helps us enter into relationship with God, the source of true joy.

"The joy of the Christian comes from faith and from the encounter with Jesus Christ, the reason for our happiness," the Pope continued. "The more we are rooted in Christ, the more we find inner serenity, even in the midst of everyday contradictions."

The Christian who has met Jesus cannot be "a prophet of misfortune" but must be "a witness and a herald of joy," said Francis. This is "a joy to share with others; a contagious joy that makes life's journey less tiring."

St. Paul also stressed "the grateful love of God," his generosity, mercy, patience and goodness. Christians are to be "living in an endless state of thanksgiving."

Pope Francis closed his remarks before the Angelus by entrusting the congregation to the intercession of the Virgin Mary.

"She is 'the cause of our joy,' not only because she is the Mother of Jesus, but because she continually leads us to Him," he said.

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After the Angelus, the Pope called for the release of six women religious kidnapped in Iguoriakhi in Nigeria's southern Edo State.

On Nov. 13 gunmen abducted the sisters, three professed women and three aspirants, from their convent. There have been no claims of responsibility for the crime in a country where kidnapping for ransom has become common.

"I unite my heart to the appeal of the bishops of Nigeria for the liberation of the Sisters of the Eucharistic Heart of Christ," he said.

"I pray with insistence for them and for all the other persons who find themselves in this painful condition," he continued, adding "may they all, on the occasion of Christmas, finally return to their homes."