CIC 548 The signs worked by Jesus attest that the Father has sent him. They invite belief in him.1 To those who turn to him in faith, he grants what they ask.2 So miracles strengthen faith in the One who does his Father’s works; they bear witness that he is the Son of God.3 But his miracles can also be occasions for “offence”;4 they are not intended to satisfy people’s curiosity or desire for magic Despite his evident miracles some people reject Jesus; he is even accused of acting by the power of demons.5

CIC 2616 Prayer to Jesus is answered by him already during his ministry, through signs that anticipate the power of his death and Resurrection: Jesus hears the prayer of faith, expressed in words (the leper, Jairus, the Canaanite woman, the good thief)6 or in silence (the bearers of the paralytic, the woman with a hemorrhage who touches his clothes, the tears and ointment of the sinful woman).7 The urgent request of the blind men, “Have mercy on us, Son of David” or “Jesus, Son of David, have mercy on me!” has-been renewed in the traditional prayer to Jesus known as the Jesus Prayer: “Lord Jesus Christ, Son of God, have mercy on me, a sinner!”8 Healing infirmities or forgiving sins, Jesus always responds to a prayer offered in faith: “Your faith has made you well; go in peace.”
St. Augustine wonderfully summarizes the three dimensions of Jesus’ prayer: “He prays for us as our priest, prays in us as our Head, and is prayed to by us as our God. Therefore let us acknowledge our voice in him and his in us.”9

CIC 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.10 By it the heart is opened to human wretchedness and the Savior’s mercy.

1 cf. Jn 5:36; 10:25, 38.
2 Cf. Mk 5:25-34; 10:52; etc.
3 Cf. Jn 10:31-38.
4 Mt 11:6.
5 Cf. Jn 11:47-48; Mk 3:22.
6 Cf. Mk 1:40-41; 5:36; 7:29; Cf. Lk 23:39-43.
7 Cf. Mk 25; 5:28; Lk 7:37-38.
8 Mt 9:27, Mk 10:48.
9 St. Augustine, En. in Ps. 85, 1: PL 37, 1081; cf. GILH 7.
10 Cf. Mk 10:46-52; Lk 18:13.