The ultimate thirst of men cries out for the Holy Spirit. He, and he alone, is, at a profound level, the fresh water without which there is no life. In the image of a spring, of the water that irrigates and transforms a desert, that man meets like a secret promise, the mystery of the Spirit becomes visible in an ineffable fashion that no rational meditation can encompass. In man’s thirst, and in his being refreshed by water, is portrayed that infinite, far more radical thirst that can be quenched by no other water… The Holy Spirit is eternally, of his very nature, God’s gift, God as wholly self-giving, God as sharing himself, as gift. In that sense, the inner reason and basis for creation and salvation history do after all lie in this quality of being of the Holy Spirit, as donum and datum… He is the content of Christian prayer. He is the only gift worthy of God: as God, God gives nothing other than God; he gives himself and thereby everything. That is why properly Christian prayer, again, does not beg for just anything; rather, it begs for the gift of God that is God himself, begs for him.
Text from Pope Benedict XVI