The third Person of the Blessed Trinity is the Holy Ghost. To Him we attribute the work of regeneration, revelation, and sanctification. On Pentecost the Holy Ghost was sent by Christ to the Apostles. He is the source of the Church’s holiness and spiritual unity.
O holy and divine Spirit. I will no longer live to myself; but I will spend all the days that remain for me in this life in loving Thee and pleasing Thee. Therefore I beseech Thee to grant me the gift of prayer. Do Thou descend into my heart, and teach me to pray as I ought. Give me strength not to leave it off through weariness in times of aridity; and give me the spirit of prayer, that is to say, the grace constantly to pray to Thee, and to use those prayers which are dearest to Thy Sacred Heart. I was once lost through my sins; but I see, from all the kindnesses I have received from Thee, that Thou willest that I should be saved and become a saint; and I desire to become a saint to give Thee pleasure, and that I may love Thy infinite goodness more and more. I love Thee, O my sovereign good, my love, my all; and because I love Thee I give myself entirely to Thee. O Mary, my hope, do thou protect me!
St. Alphonsus De Liguori