Rome, Italy, Mar 13, 2015 / 10:05 am (CNA/EWTN News).- During his homily for a Lenten penitential service, Pope Francis announced an extraordinary Jubilee to start at the end of the year, which will be dedicated to a theme close to the pontiff’s heart: mercy.

“Dear brothers and sisters, I have thought about how the Church can make clear its mission of being a witness of mercy,” the Pope told attendees of his March 13 penitential liturgy in St. Peter’s Basilica.

“It's a journey that starts with a spiritual conversion. For this reason I have decided to declare an Extraordinary Jubilee that has the mercy of God at its center. It will be a Holy Year of Mercy.”

The biblical passage for the Holy Year's theme is from Luke Chapter 6 verse 36, in which Jesus tells his disciples, “Be merciful as your Father is merciful.”

“I am convinced that the whole Church will be able to find in this Jubilee the joy of rediscovering and making fruitful the mercy of God, with which we are all called to give consolation to every man and every woman of our time,” Francis said, and entrusted the Holy Year to Mary, Mother of Mercy.

Pope Francis made his announcement during a penitential liturgy opening the second “24 Hours for the Lord” event, which he originally called for in Lent of last year.

An initiative of the Pontifical Council for the Promotion of the New Evangelization, the event is designed to widen access to the Sacrament of Confession by having parishes open their doors for an extended period of time with priests available to those who come.

Francis’ announcement of the Extraordinary Jubilee for mercy not only falls on the opening of the 24 hours for the Lord event, which follows the theme “God rich in mercy,” but also the two year anniversary of his pontificate.

The Jubilee, also called a Holy Year, will open this year on Dec. 8 – the Solemnity of the Immaculate Conception – and will close Nov. 20, 2016 with the Solemnity of Our Lord Jesus Christ, King of the Universe.

It will also coincide with the 50th anniversary of the closing of the Second Vatican Council in 1965. The Jubilee will be organized by the Pontifical Council for the New Evangelization.

Sunday readings during Ordinary Time for the Holy Year will be taken from the Gospel of Luke, as he is often referred to as “the evangelist of mercy.” Among the well-known parables of mercy present in Luke’s Gospel are those of the lost sheep, the lost coin and the merciful father.

The official announcement of the Jubilee will take place on Divine Mercy Sunday, the Sunday after Easter, with a public proclamation in front of the Holy Door of St. Peter’s Basilica.

Each of the four papal basilicas in Rome has a holy door, which are normally sealed shut from the inside so that they cannot be opened. The doors are only opened during Jubilee years so that pilgrims can enter through them in order to gain the plenary indulgence that is connected with the Jubilee.

The rite of the opening of the Holy Door is intended to symbolically illustrate the idea that the Church’s faithful are offered an “extraordinary path” toward salvation during the time of Jubilee.

After the Holy Door opens in St. Peter’s Basilica, those of the other three Roman basilicas, St. John Lateran, St. Paul Outside the Walls and St. Mary Major, will be opened.

In ancient Hebrew tradition, the Jubilee Year was celebrated every 50 years and was intended to restore equality among the children of Israel by providing opportunities for families who had lost their property and even their personal freedom to regain them.

It was also a year in which the wealthy were reminded that their Israelite slaves would again become their equals and regain their rights.

The Catholic tradition of practicing the Holy Year began with Pope Boniface VIII in 1300, and since 1475 an Ordinary Jubilee has been celebrated every 25 years in order to allow each generation to experience at least one during their lifetime.

However, as is the case with Pope Francis’ 2016 Holy Year of Mercy, an extraordinary Jubilee can be called for a special occasion or for an event that has a particular importance.

Until now there have only been 26 ordinary Jubilee celebrations, the last of which was the Jubilee of 2000.

The Holy Year is traditionally a year of forgiveness of sins and also the punishment merited by one’s sins. It is also a year for reconciliation between enemies, conversion and receiving the Sacrament of Reconciliation.

The first extraordinary Jubilee was called in 16th century, and the most recent have been in 1933, when Pope Pius XI called one to celebrate 1900 years of Redemption, and in 1983 when St. John Paul II proclaimed one to honor 1950 years of Redemption.

Mercy is a theme that is dear to Francis, and is the central topic of his episcopal motto “miserando atque eligendo,” which he chose when ordained a bishop in 1992.

One translation of the motto, taken from a homily given by St. Bede on Jesus’ calling of St. Matthew, is “with eyes of mercy.”

In his first Angelus address as the Bishop of Rome, March 17, 2013, Francis spoke of “Feeling mercy...this word changes everything.”

Mercy, he said then, “is the best thing we can feel: it changes the world. A little mercy makes the world less cold and more just. We need to understand properly this mercy of God, this merciful Father who is so patient.”

In the English version of his first Apostolic Exhortation “Evangelii Gaudium,” the word “mercy” appears 32 times.