Prayer is a central theme in the common Bible of the Abrahamic religions, where various forms of prayer appear; the most common forms being petition, thanksgiving and worship. When people pray as a form of petition, they hope for a certain outcome either in the physical world, e.g. the recovery of a person from an ailment, or in the spiritual world, e.g. the repose of a soul via a prayer for the dead. However, not all prayers include direct petitions, for they may be Acts of Reparation which do not involve a petition for a living or deceased beneficiary, but aim to repair the sins of others, e.g. as Acts of Reparation to Jesus Christ.
Catholic tradition has had a long history of making specific promises to those who pray and emphasizing the power of prayer to change the world. Prayer has been used as a method, and a tool for strengthening the Church, and its members at the individual level, both before the Protestant Reformation in the 16th century and thereafter in the Catholic context.
Belief in Prayer
The belief in prayer is central to Christianity. In the Gospel, Jesus often encouraged prayer and offered prayers. In the Gospel of John, after "looking towards heaven", in John 17:20 Jesus prayed to The Father for his Apostles and followers:
- "I pray also for those who will believe in me through their message, that all of them may be one." 
- "Truly I say to you, if you have faith the size of a mustard seed, you will say to this mountain, 'Move from here to there,' and it will move; and nothing will be impossible to you".
Yet the Bible does not simply depict prayer as a "channel for submitting petitions" to God, but at times portrays it as a method of obtaining personal strength. For instance, when Jesus prayed during his Agony in the Garden in Gethsemane just before he was betrayed for Crucifixion, Luke 22:43 states:
- "An angel from heaven appeared to Him and strengthened Him"
Almost 2,000 years later Catholic figures continue to reinforce the belief in prayer and emphasize its importance. For instance, in his book "An Invitation to Prayer" Pope John Paul II emhasized prayer as the cornerstone of Catholic life . Similarly, in her book "Everything Starts from Prayer" Mother Teresa of Calcutta stressed the importance of prayer in every aspect of life to Catholics, from multiple perspectives .
From the viewpoint of the psychology of prayer, in their book Ann and Barry Ulanov, suggest that belief in prayer has deep roots in the human psyche and although it may be suppressed by rational and scientific debate, it often resurfaces at times of distress for it is a primary language for communicating with the supernatural world.
Despite the promises associated with the power of prayer, the direct measurement of its effect is often discouraged in the Abrahamic religions, e.g. Deuteronomy 6:16 states: "You shall not test the Lord thy God".
Promise of prayer
The 1,189 chapters of the Bible include 1,260 promises, a number of which relate to prayer. But long after the last book of the Bible was written, Christian leaders, be they saints, preachers or popes have continued to make further promises to the faithful who prayed.
Christian tradition holds that fifteen specific prayers and twenty one promises were revealed to Saint Bridget of Sweden (also known as Saint Brigitta) by Jesus in Rome in the 14th century. Pope Pius IX approved these promises in 1862 and Pope Benedict XV agreed with them. The Holy See published the prayers and promises by decree of November 18, 1966, in volume 58 of Acta Apostolicae Sedis. According to Saint Birgitta, Jesus made twenty one specific promises to anyone who recited the fifteen prayers for a whole year. The promises range from the deliverance of other souls from purgatory, to the salvation of the person performing the prayers and their avoidance of sudden death.
Saint Marguerite Marie Alacoque
From 1673 to 1675 Saint Marguerite Marie Alacoque reported a series of visions of Christ speaking to her which led to her founding the Devotion of the Sacred Heart of Jesus. Initially, her life, actions and writings became the subject of extreme scrutiny by the Catholic Church, but she was eventually declared a saint in 1920 and the Feast of the Sacred Heart is now officially celebrated 19 days after Pentecost. As part of her visions of Jesus and Mary she stated that Jesus gave her twelve specific promises. The promises were directed towards those who pray and practice the Devotion to the Sacred Heart of Jesus. The promises range from receiving all the graces necessary for their state of life to the grace of final repentance provided they receive Communion on the First Friday of nine consecutive months.
Holy Face of Jesus
Contemplation of, and prayers to, the Holy Face of Jesus are believed by some Catholics to have a positive spiritual effect, based on the Catholic devotion approved by Pope Leo XIII in 1885. According to Sister Marie of St Peter, a Carmelite nun who lived in Tours France, in 1844 she had a vision in which Jesus told her:
- "Those who will contemplate the wounds on My Face here on earth, shall contemplate it radiant in heaven."
She reported that she saw Saint Veronica wiping away the spit and mud from the face of Jesus with her veil on the way to Calvary. According to Sister Marie of St Peter, in her visions Jesus told her that He desired devotion to His Holy Face in reparation for sacrilege and blasphemy. She wrote The Golden Arrow Holy Face Devotion (Prayer) which she said was dictated to her by Jesus. She quoted Jesus as saying in her visions:
- "Oh if you only knew what great merit you acquire by saying even once, Admirable is the Name of God, in a spirit of reparation for blasphemy."
The devotion was promoted by the Venerable Leo Dupont and was later extended, when decades later an Italian nun, Sister Maria Pierina De Micheli associated the image of the Holy Face of Jesus from the Shroud of Turin with it in 1958 and made the first Holy Face Medal bearing the image of the Holy Face of Jesus. The Holy Face Medal was already referred to in the writings of Sister Marie of St Peter, as a Holy Face Coin almost 90 years earlier. Sister Marie of St Peter wrote that Jesus told her:
- "As in a kingdom they can procure all that is desired with a coin stamped with the King's effigy, so in the Kingdom of Heaven they will obtain all they desire with the precious coin of My Holy Face."
The first Holy Face Medal was offered to Pope Pius XII who accepted it and approved of the devotion.
Among the many Catholic prayers, the Holy Rosary is one of the most prominent, and most often recited prayers. Of course, since the words to the rosary include the words to the Our Father and the Hail Mary prayers, the frequency of the Our Father and the Hail Mary by definition exceed that of the rosary.
There are no exact data on the number of daily rosaries prayed around the world, but to get an idea of the spread of the rosary within Roman Catholics, it is worth noting that literally hundreds of millions of rosaries have been reportedly made and distributed free of charge by volunteers worldwide. A number of rosary-making clubs exist around the world for the purpose of making and distributing rosaries to missions, hospitals, prisons, etc. free of charge. The largest such non-profit organization in the United States is Our Lady's Rosary Makers whose 17,000 members annually distribute roughly 7 million free rosaries.
The significance of the rosary is widely emphasized in Catholic teachings, e.g. in his 1981 apostolic exhortation Familiaris Consortio Pope John Paul II said:
Saint Louis de Montfort's widely read book The Secret of the Rosary discusses the religious and mystical views on the rosary from multiple perspectives . Interestingly, Pope John Paul II was influenced by de Montfort's writings, in that he singled out de Montfort in his Redemptoris Mater encyclical and in an address to the Montfortian Fathers, said that reading one of the saint's books  had been a "decisive turning point" in his life.
The rosary has also been mentioned as a source of inspiration by a number Roman Catholic figures. For instance, in his encyclical Rosarium Virginis Mariae Pope John Paul II discusses the inspiration of the rosary and how his motto "Totus Tuus" was inspired by the writings of Saint Louis de Montfort.
Some Roman Catholics sources suggest that through Saint Dominic and Blessed Alan de Rupe the Blessed Virgin Mary made fifteen specific promises to Christians who pray the rosary, although other sources argue that the rosary and these promises have their roots in the preaching of Alan de Rupe between 1470-1475 and not Saint Dominic. And there are sources which try to seek a middle ground to these two views.
Patrick Cardinal Hayes of New York provided his imprimatur in support of these promises and the first viewpoint. The fifteen rosary promises range from protection from misfortune to meriting a high degree of glory in heaven.
The promises attributed to the rosary continue to appear and be extended in the reported visions of Jesus and Mary. For instance, the Carmelite nun, sister Lucia dos Santos stated that she was told in the Our Lady of Fatima messages:
- "There is no problem, I tell you, no matter how difficult it is, that we cannot resolve by the prayer of the Holy Rosary." 
The rosary was also featured in the reported visions of Saint Bernadette Soubirous at Our Lady of Lourdes. In his book The Power of the Rosary Rev. Albert Shamon discusses the promises attributed to the rosary in various reported visions such as Our Lady of Fatima and Međugorje.
Other prayers and promises
Shoulder wound of Jesus
In the twelfth century Pope Eugenius III approved of the promises with regards to the Prayer to the shoulder wound of Jesus which according to Saint Bernard of Clairvaux was the wound that inflicted the most pain on Jesus in Calvary, caused by the rough wood of the Cross that Christ carried. The modern version of the prayer bears the imprimatur of Bishop Thomas D. Bevan.
Chaplet of Saint Michael
The Chaplet of Saint Michael is due to a reported vision of Saint Michael the Archangel to the Portuguese Carmelite nun Antonia d'Astonac. According to Antonia, Saint Michael asked her to honor him by nine salutations to the nine Choirs of Angels and promised that whoever would practice this devotion in his honor would have, when approaching Holy Communion, an escort of nine angels chosen from each of the nine Choirs. In addition, for those who would recite the Chaplet daily, he promised his continual assistance and that of all the holy angels during life.
Prayer as a source of strength
In the Christian tradition personal prayer has been positioned as a source for personal strength, just as Jesus was strengthened during prayer in Gethsemane in Luke 22:43, i.e. in first person prayer. And it has been used in second person prayer to provide encouragement to others. Moreover, prayer performed corporately in the presence of fellow believers has been encouraged.
First person mental prayer
Mental prayer is a form of prayer recommended in the Catholic Church whereby one loves God through dialogue with him, meditating on his words, and contemplating him. It is a time of silence focused on God and one's relationship with him. It is distinguished from vocal prayers which use set prayers, although mental prayer can proceed by using vocal prayers in order to improve dialogue with God.
Mental prayer is recommended in the Catholic Church as a source of spiritual strength and according to Saint Alphonsus Liguori "all saints have become saints by mental prayer".
Second person prayer
Prayer has been used in the Catholic tradition to provide a sense of hope, perseverance and strength to others, knowing that they are being prayed for. In this case, the person performing the prayer notifies the beneficiary that the prayer is taking place. For instance, Pope Pius XII said of the Venerable Gabriele Allegra’s attempt to translate the Bible to Chinese:
- “Tell this young priest that he has my special blessing and that I will pray for him every day. He will meet with many difficulties, but let him not lose courage. Nothing is impossible for him who prays, wills and studies. I shall not live to see this work completed, but I shall pray for him in heaven”.
- “Again, I tell you that if two of you on earth agree about anything you ask for, it will be done for you by my Father in heaven. For where two or three come together in my name, there am I with them." 
Power of prayer
The Bible attributes effectiveness to prayers performed by the faithful. Building on the statement in James 5:16 that:
- The prayer of a righteous man is powerful and effective.
Catholic tradition has for centuries continued to attribute power to prayers performed by believers.
Beyond the physical
The belief in the power of Christian prayer to change the world beyond physical efforts has been emphasized in the Catholic tradition over the centuries. The statement in 2 Corinthians 10:4-5 that:
- "The weapons we fight with are not the weapons of the world. On the contrary, they have divine power to demolish strongholds." 
reflects the belief that prayer has more power than physical force. Similarly, 2,000 years later, according to WikiQuote, Mother Teresa said:
- "When I was crossing into Gaza, I was asked at the checkpost whether I was carrying any weapons. I replied: Oh yes, my prayer books."
Yet Mother Teresa did not perceive prayer as a threatening force, but as a force for service, love and peace, for she wrote:
- "The fruit of silence is prayer; the fruit of prayer is faith; the fruit of faith is love; the fruit of love is service; the fruit of service is peace.
Similarly, as the starting words to the prayer of Saint Francis suggest:
- "Lord, make me an instrument of Thy peace; where there is hatred, let me sow love; where there is injury, pardon ..."
Catholic tradition positions prayer primarily as a force for seemingly non-physical effects such as peace, forgiveness and pardon.
Long term prayer
In the Christian and Catholic traditions, there are many legends about the power of long term prayer. In the fourth century, Saint Monica of Hippo is said to have prayed for the conversion of her son Augustine for fourteen years and he eventually became an influential figure in Christian thought.
Another example of long term prayer often mentioned in the Roman Catholic tradition is that of the Venerable Leo Dupont, also known as the Holy Man of Tours. Dupont was said to have prayed for 30 years for the public release of messages from sister Marie of St Peter in 1844 regarding the Holy Face of Jesus. Shortly before Dupont's death in 1876, Charles-Théodore Colet was appointed as the Archbishop of Tours and allowed the records to be made public. Dupont's followers attribute this to Dupont's 30 years of prayer, 10 years of which consisted of almost constant prayer before a candle burning before an image of the Holy Face of Jesus. In 1885 the Devotion to the Holy Face of Jesus was approved by Pope Leo XIII and in 1958 Pope Pius XII declared the Feast of the Holy Face of Jesus as Shrove Tuesday (the Tuesday before Ash Wednesday) for all Roman Catholics. Dupont eventually became known as the Apostle of the Holy Face.
Prayer as reparation
Roman Catholic tradition includes specific prayers and devotions as acts of reparation. These prayers do not involve a petition for a living or deceased beneficiary, but aim to repair the sins of others, e.g. when the name of Jesus Christ is taken in vain, or for the repair of the sin of blasphemy. Some such prayers are provided in the Raccolta Catholic prayer book, approved by a Decree of 1854, and published by the Holy See in 1898.
Specific Catholic organizations with the purpose of promoting prayer as reparation have been formed. For instance, the Archconfraternity of Reparation for blasphemy and the neglect of Sunday was founded by Msgr. Pierre Louis Parisis in 1847 and the Archconfraternity of the Holy Face was founded in 1851 by the Venerable Leo Dupont, the "Holy Man of Tours".
Learning to pray
Although many promises are associated with prayer, in his book "The Way to Christ" Pope John Paul II warned against "mechanical prayer" and the need for self-reflection before prayer. And in his message for the 42nd "World Day of Prayer" he said:
- "We have to learn to pray: as it were learning this art ever anew from the lips of the Divine Master himself, like the first disciples: 'Lord, teach us to pray!' (Lk 11:1)."
In his book The Secret of the Rosary Saint Louis de Montfort went into significant detail on how to prepare to say a single rosary. He emphasized purity of intention before the rosary begins, the need for attention, focus and reverence during the prayer and the necessity of fighting distractions .
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