A selected quote from the Catechism of the Catholic Church in honor of the Year of Faith (October 11, 2012 - November 24, 2013)
326 The Scriptural expression "heaven and earth" means all that exists, creation in its entirety. It also indicates the bond, deep within creation, that both unites heaven and earth and distinguishes the one from the other: "the earth" is the world of men, while "heaven" or "the heavens" can designate both the firmament and God's own "place" - "our Father in heaven" and consequently the "heaven" too which is eschatological glory. Finally, "heaven" refers to the saints and the "place" of the spiritual creatures, the angels, who surround God.
327 The profession of faith of the Fourth Lateran Council (1215) affirms that God "from the beginning of time made at once (simul) out of nothing both orders of creatures, the spiritual and the corporeal, that is, the angelic and the earthly, and then (deinde) the human creature, who as it were shares in both orders, being composed of spirit and body."
328 The existence of the spiritual, non-corporeal beings that Sacred Scripture usually calls "angels" is a truth of faith. The witness of Scripture is as clear as the unanimity of Tradition.
331 Christ is the center of the angelic world. They are his angels: "When the Son of man comes in his glory, and all the angels with him. . " They belong to him because they were created through and for him: "for in him all things were created in heaven and on earth, visible and invisible, whether thrones or dominions or principalities or authorities - all things were created through him and for him." They belong to him still more because he has made them messengers of his saving plan: "Are they not all ministering spirits sent forth to serve, for the sake of those who are to obtain salvation?"
332 Angels have been present since creation and throughout the history of salvation, announcing this salvation from afar or near and serving the accomplishment of the divine plan: they closed the earthly paradise; protected Lot; saved Hagar and her child; stayed Abraham's hand; communicated the law by their ministry; led the People of God; announced births and callings; and assisted the prophets, just to cite a few examples. Finally, the angel Gabriel announced the birth of the Precursor and that of Jesus himself.
336 From its beginning until death, human life is surrounded by their watchful care and intercession. "Beside each believer stands an angel as protector and shepherd leading him to life."203 Already here on earth the Christian life shares by faith in the blessed company of angels and men united in God.
337 God himself created the visible world in all its richness, diversity and order. Scripture presents the work of the Creator symbolically as a succession of six days of divine "work", concluded by the "rest" of the seventh day. On the subject of creation, the sacred text teaches the truths revealed by God for our salvation, permitting us to "recognize the inner nature, the value and the ordering of the whole of creation to the praise of God."
341 The beauty of the universe: The order and harmony of the created world results from the diversity of beings and from the relationships which exist among them. Man discovers them progressively as the laws of nature. They call forth the admiration of scholars. The beauty of creation reflects the infinite beauty of the Creator and ought to inspire the respect and submission of man's intellect and will.
342 The hierarchy of creatures is expressed by the order of the "six days", from the less perfect to the more perfect. God loves all his creatures and takes care of each one, even the sparrow. Nevertheless, Jesus said: "You are of more value than many sparrows", or again: "Of how much more value is a man than a sheep!"
343 Man is the summit of the Creator's work, as the inspired account expresses by clearly distinguishing the creation of man from that of the other creatures.
344 There is a solidarity among all creatures arising from the fact that all have the same Creator and are all ordered to his glory: May you be praised, O Lord, in all your creatures, especially brother sun, by whom you give us light for the day; he is beautiful, radiating great splendor, and offering us a symbol of you, the Most High...
May you be praised, my Lord, for sister water,
who is very useful and humble, precious and chaste.
May you be praised, my Lord, for sister earth,
our mother, who bears and feeds us,
and produces the variety of fruits
and dappled flowers and grasses
Praise and bless my Lord,
give thanks and serve him in all humility.