June Mystery of Faith - Sacred Heart

Being a cradle Catholic who was raised in the post-VII Church, there is much I don't know about the richness of my religion. My faith is in its infancy in many respects and I am working to change that. I was looking for a book that contained information on Catholic home traditions that I could start with my children. I found a book at the homeschool conference, Catholic and Loving It, Traditions for a New Generation, by Sabitha Narendran and Andrew Salzmann, that covers many Catholic traditions. I'd link to it on Amazon, but it just was released this month and wasn't yet available. Anyway, it is kind of light in its content and discussion of various things (since what Catholic topic couldn't be a doctoral thesis), but at least it talks about the various traditions and then you can go do more digging yourself. One thing I just learned from the book is that June is the month associated with the Mystery of the Sacred Heart and the Feast Day comes with an indulgence.
From the text, p. 39:

Popular images of the Sacred Heart can seem "weird," juxtaposing Christ's sugar-sweet facial expressions and bloody, tortured heart. Yet behind whatever cultural barriers separate us from this devotion, lies the central truth of the heart of Jesus: God loves us with a human heart and a human love, with a love that extends through pain and death, "even death on a cross," to offer us redemption.

The Feast of the Sacred Heart falls nineteen days after Pentecost, which is this coming Friday. (There are many aspects of Devotion to the Sacred Heart, ie: First Fridays, enthronment, etc., I'm only going to deal with the Feast and the Indulgence.) Many Catholics prepare for this Feast by beginning a Novena to the Sacred Heart on the Feast of Corpus Christi, which is the Thursday of the week before. On the Feast of the Sacred Heart itself, one can gain a plenary indulgence by making an Act of Reparation to the Sacred Heart (along with the usual requirements of Confession, Communion and prayers for the Holy Father).

Act of Reparation to the Sacred Heart / Actus reparationis

Most sweet Jesus, whose overflowing charity for men is requited by so much forgetfulness, negligence and contempt, behold us prostrate before Thee, eager to repair by a special act of homage the cruel indifference and injuries to which Thy loving Heart is everywhere subject.

Mindful, alas! that we ourselves have had a share in such great indignities, which we now deplore from the depths of our hearts, we humbly ask Thy pardon and declare our readiness to atone by voluntary expiation, not only for our own personal offenses, but also for the sins of those, who, straying far from the path of salvation, refuse in their obstinate infidelity to follow Thee, their Shepherd and Leader, or, renouncing the promises of their baptism, have cast off the sweet yoke of Thy law.

We are now resolved to expiate each and every deplorable outrage committed against Thee; we are now determined to make amends for the manifold offenses against Christian modesty in unbecoming dress and behavior, for all the foul seductions laid to ensnare the feet of the innocent, for the frequent violations of Sundays and holydays, and the shocking blasphemies uttered against Thee and Thy Saints. We wish also to make amends for the insults to which Thy Vicar on earth and Thy priests are subjected, for the profanation, by conscious neglect or terrible acts of sacrilege, of the very crimes of nations who resist the rights and teaching authority of the Church which Thou hast founded.

Would that we were able to wash away such abominations with our blood. We now offer, in reparation for these violations of Thy divine honor, the satisfaction Thou once made to Thy Eternal Father on the Cross and which Thou continuest to renew daily on our Altars; we offer it in union with the acts of atonement of Thy Virgin Mother and all the Saints and of the pious faithful on earth; and we sincerely promise to make recompense, as far as we can with the help of Thy grace, for all neglect of Thy great love and for the sins we and others have committed in the past. Henceforth, we will live a life of unswerving faith, of purity of conduct, of perfect observance of the precepts of the Gospel and especially that of charity. We promise to the best of our power to prevent others from offending Thee and to bring as many as possible to follow Thee.

O loving Jesus, through the intercession of the Blessed Virgin Mother, our model in reparation, deign to receive the voluntary offering we make of this act of expiation; and by the crowning gift of perseverance keep us faithful unto death in our duty and the allegiance we owe to Thee, so that we may all one day come to that happy home, where with the Father and the Holy Spirit Thou livest and reignest, God, forever and ever. Amen.

Note:
A partial indulgence is granted to those who recite this prayer. A plenary indulgence is granted if it is publicly recited on the feast of the Most Sacred Heart of Jesus. This prayer was prescribed to be recited on this feast by Pope Pius XI.

Devotion to the Sacred Heart had been practiced for ages, but it took the onset of Protestantism and the errors of the Janeists, before God rose up another saint. Margaret Mary Alacoque was a simple nun of the order of the Visitation in Paray-le-Monial, France, founded in the early in the seventeenth century by St. Francis de Sales. The order was known for their humility and selflessness and Margaret Mary excelled in these virtues.

In December of 1673, and covering a period of eighteen months, Margaret Mary began to have experiences that began while she was kneeling in the chapel. She felt encapsulated by the Divine Presence, and heard the Lord inviting her to take the place which St. John had occupied at the Last Supper. The Lord told her that the love of His heart must spread and manifest itself to men, and He would reveal its graces through her.

"And He showed me that it was His great desire of being loved by men and of withdrawing them from the path of ruin into which Satan hurls such crowds of them, that made Him form the design of manifesting His Heart to men, with all the treasures of love, of mercy, of grace, of sanctification and salvation which it contains, in order that those who desire to render Him and procure for Him all the honor and love possible, might themselves be abundantly enriched with those divine treasures of which this Heart is the source.

He should be honored under the figure of this Heart of flesh, and its image should be exposed...He promised me that wherever this image should be exposed with a view to showing it special honor, He would pour forth His blessings and graces. This devotion was the last effort of His love that He would grant to men in these latter ages, in order to withdraw them from the empire of Satan which He desired to destroy, and thus to introduce them into the sweet liberty of the rule of His love, which He wished to restore in the hearts of all those who should embrace this devotion."..... "The devotion is so pleasing to Him that He can refuse nothing to those who practice it."

from Revelations of Our Lord to St. Margaret Mary Alacoque

Needless to say, like so many saints before and after her, when Margaret Mary went to her Mother Superior to tell her about what had happened, she was reprimanded for her presumption. The stress began to impair her heath and she became so ill that those around her feared for her life. Eventually, the Mother Superior reconsidered Margaret Mary's story and vowed that if her Margaret Mary's life was spared, she would take it as a sign that the visions and messages were truly from God. When Margaret Mary recovered, the Superior asked some theologians to hear Margaret Mary's story. The priests concluded that Margaret Mary was delusional. Another priest, Father Claude de la Columbiere, a Jesuit who was assigned as the confessor at the convent, talked to her and was completely convinced of the genuineness of the revelations. Through Father Columbiere's writings about Margaret Mary's experiences, the Devotion to the Sacred Heart finally began to spread throughout Europe.

Her feast day is October 17.

The June Prayer (noted in the Catholic and Loving it book) from the Raccolta, 263:
O most holy Heart of Jesus, fountain of every blessing, I adore you, I love you, and with a lively sorrow for my sins, I offer you this poor heart of mine. Make me humble, patient, pure and wholly obedient to your will. Grant, good Jesus, that I may live in you and for you. Protect me in the midst of danger; comfort me in my afflictions; give me health of body, assistance in my temporal needs, your blessing on all that I do, and the grace of a holy death.