1. Spiritual healing is necessary because of the wound of original sin.
Our fallen nature makes us vulnerable to sin-sickness, which is why we are all in need of the healing that comes from Jesus Christ. The first step in the healing process is to acknowledge that we are in need of healing:
“Man, tempted by the devil, let his trust in his Creator die in his heart and, abusing his freedom, disobeyed God's command. This is what man's first sin consisted of. All subsequent sin would be disobedience toward God and lack of trust in his goodness.” - Catechism 397
"The harmony in which they had found themselves, thanks to original justice, is now destroyed: the control of the soul's spiritual faculties over the body is shattered; the union of man and woman becomes subject to tensions, their relations henceforth marked by lust and domination. Harmony with creation is broken: visible creation has become alien and hostile to man. Because of man, creation is now subject "to its bondage to decay". Finally, the consequence explicitly foretold for this disobedience will come true: man will "return to the ground", for out of it he was taken. Death makes its entrance into human history." - Catechism 400
2. Jesus Christ is the Divine Physician who has the power to heal the whole person.
“The Lord Jesus Christ, physician of our souls and bodies, who forgave the sins of the paralytic and restored him to bodily health, has willed that his Church continue, in the power of the Holy Spirit, his work of healing and salvation, even among her own members. This is the purpose of the two sacraments of healing: the sacrament of Penance and the sacrament of Anointing of the Sick.” - Catechism 1421
“Jesus has the power not only to heal the whole man, soul and body; he is the physician the sick have need of (cf Mk. 2:17). His preferential love for the sick has not ceased through the centuries to draw the very special attention of Christians towards all those who suffer in body and soul." - Catechism 1503
3. Our spiritual healing begins with the Sacrament of Baptism and continues with the Sacraments of the Eucharist and Confession.
[Baptism] signifies and actually brings about death to sin and entry into the life of the Most Holy Trinity through configuration to the Paschal mystery of Christ." - Catechism 1239
"Almighty and Eternal God, behold I come to the Sacrament of Your only-begotten Son, our Lord Jesus Christ. As one sick, I come to the Physician of life; unclean, to the Fountain of mercy; blind, to the Light of eternal splendor; poor and needy, to the Lord of heaven and earth. Therefore, I beg of You, through Your infinite mercy and generosity, heal my weakness, wash my uncleanness, give light to my blindness, enrich my poverty, and clothe my nakedness." - St. Thomas Aquinas
"Tell souls where they are to look for solace; that is, in the Tribunal of Mercy [the Sacrament of Reconciliation]. There the greatest miracles take place and are incessantly repeated...Were a soul like a decaying corpse so that from a human standpoint, there would be no [hope of] restoration and everything would be already lost, it is not so with God. The miracle of Divine Mercy restores that soul in full." - Jesus to St. Faustina
