Haurietis aquas (Latin: "You will draw waters") is a landmark encyclical of Pope Pius XII. Written on May 15, 1956, it was attached to the 100th anniversary of the establishment of the feast of the Sacred Heart of Jesus by Pope Pius IX. The title is derived from Isaiah 12:3, a verse which alludes to the abundance of the supernatural goods given by Jesus. Haurietis aquas made the whole Church, and not merely the Jesuits, recognize the Sacred Heart as an important dimension a Christian spirituality.
The Sacred Heart Of Jesus
Pius XII gave two reasons why the Church gives the highest form of worship to the Heart of Jesus. The first rests on the principle whereby the believers recognise that Jesus' Heart is hypostatically united to the "Person of the Incarnate Son of God Himself". The second reason is derived from the fact that the Heart is the natural sign and symbol of Jesus' boundless love for the humans. The encyclical recalls that for human souls the wound in Christ's side and the marks left by the nails have been "the chief sign and symbol of that love" that ever more incisively shaped their life from within.
The Pope describes several erroneous opinions regarding this devotion. There are those, who consider it burdensome and of little or no use to men. Others consider this devotion as a piety suited for women, and not for educated men. There are those who consider a devotion of this kind as primarily demanding penance, expiation and the other virtues which they call "passive," meaning thereby that they produce no external results. Hence they do not think it suitable to re-enkindle the spirit of piety in modern times  .The encyclical replies with Pope Pius XI: The veneration of the Sacred Heart is a summary of all our religion and, moreover, a guide to a more perfect life. It more easily leads our minds to know Christ the Lord intimately and more effectively turns our hearts to love Him more ardently and to imitate Him more perfectly."  Haurietis Aquas opines that the Sacred Heart never ceased, and never will cease, to beat with calm. It will never cease to symbolize the threefold love with which Jesus Christ is bound to His heavenly Father and the entire human race 
The Heart of Jesus Christ loves the human race but as a human and divine heart. It began to beat with love at once human and divine after the Virgin Mary generously pronounced her "Fiat";  The Sacred Heart of Jesus shares in a most intimate way in the life of the Incarnate Word, and is thus a kind of instrument of the Divinity. Therefore, "in the carrying out of works of grace and divine omnipotence, His Heart, no less than the other members of His human nature is a symbol of that unbounded love". 
- After our Lord had ascended into heaven with His body adorned with the splendors of eternal glory and took His place by the right hand of the Father, He did not cease to remain with His Spouse, the Church, by means of the burning love with which His Heart beats. For He bears in His hands, feet and side the glorious marks of the wounds which manifest the threefold victory won over the devil, sin, and death.
- Nothing therefore prevents our adoring the Sacred Heart of Jesus Christ as having a part in and being the natural and expressive symbol of the abiding love with which the divine Redeemer is still on fire for mankind. Though it is no longer subject to the varying emotions of this mortal life, yet it lives and beats and is united inseparably with the Person of the divine Word and, in Him and through Him, with the divine Will. Since then the Heart of Christ is overflowing with love both human and divine and rich with the treasure of all graces which our Redeemer acquired by His life, sufferings and death, it is therefore the enduring source of that charity which His Spirit pours forth on all the members of His Mystical Body.
Referring to paragraph 64 of Haurietis aquas, John Paul II wrote: "If through Christ's humanity [his] love shone on all mankind, the first beneficiaries were undoubtedly those whom the divine will had most intimately associated with itself: Mary, the Mother of Jesus, and Joseph, his presumed father". In a letter on May 15, 2006 Benedict XVI wrote: "By encouraging devotion to the Heart of Jesus, the Encyclical Haurietis aquas exhorted believers to open themselves to the mystery of God and of his love and to allow themselves to be transformed by it. After 50 years, it is still a fitting task for Christians to continue to deepen their relationship with the Heart of Jesus, in such a way as to revive their faith in the saving love of God and to welcome him ever better into their lives. 
As the encyclical states, From this source, the heart of Jesus, originates the true knowledge of Jesus Christ and a deeper experience of his love. Thus, according to Benedict XVI, we will be able to understand better what it means to know God's love in Jesus Christ, to experience him, keeping our gaze fixed on him to the point that we live entirely on the experience of his love, so that we can subsequently witness to it to others.