435 The name of Jesus is at the heart of Christian prayer. All liturgical prayers conclude with the words “through our Lord Jesus Christ”. The Hail Mary reaches its high point in the words “blessed is the fruit of thy womb, Jesus.” The Eastern prayer of the heart, the Jesus Prayer, says: “Lord Jesus Christ, Son of God, have mercy on me, a sinner.” Many Christians, such as St. Joan of Arc, have died with the one word “Jesus” on their lips.
2666 But the one name that contains everything is the one that the Son of God received in his incarnation: JESUS. The divine name may not be spoken by human lips, but by assuming our humanity The Word of God hands it over to us and we can invoke it: “Jesus,” “YHWH saves.”16 The name “Jesus” contains all: God and man and the whole economy of creation and salvation. To pray “Jesus” is to invoke him and to call him within us. His name is the only one that contains the presence it signifies. Jesus is the Risen One, and whoever invokes the name of Jesus is welcoming the Son of God who loved him and who gave himself up for him.
2667 This simple invocation of faith developed in the tradition of prayer under many forms in East and West. The most usual formulation, transmitted by the spiritual writers of the Sinai, Syria, and Mt. Athos, is the invocation, “Lord Jesus Christ, Son of God, have mercy on us sinners.” It combines the Christological hymn of Philippians 2:6-11 with the cry of the publican and the blind men begging for light. By it the heart is opened to human wretchedness and the Savior’s mercy.
2668 The invocation of the holy name of Jesus is the simplest way of praying always. When the holy name is repeated often by a humbly attentive heart, the prayer is not lost by heaping up empty phrases, but holds fast to the word and “brings forth fruit with patience.” This prayer is possible “at all times” because it is not one occupation among others but the only occupation: that of loving God, which animates and transfigures every action in Christ Jesus.’