The Master of Arts Thesis of Father Jacob M. Miller, written on the topic of the Sacred Heart of Jesus and its integration into priestly spirituality. Following the historical development of the devotion to the Sacred Heart and considering the twentieth-century documents Presbyterorum Ordinis and Pastores Dabo Vobis, this thesis explores the connection between the ministerial priesthood and the Heart of Jesus Christ. Contextualized through the experiences of Saint John the Apostle where he rested on the bosom of Christ, received the Holy Eucharist at the Last Supper, and witnessed the birth of the Church from His pierced side, the thesis argues the Sacred Heart’s effectiveness in priestly spirituality for a deepened intimacy, communion, and perfection of the priest to Jesus, the true High Priest.