From the Catechism of the Catholic Church, Simplified
Creation's Destiny (302-305)
God did not make creation "complete from the beginning," but willed "a state of journeying." God always guides all creation toward its ultimate perfection by Divine Providence. "By his providence God protects and governs all things which he has made" (First Vatican Council). God's care for every creature (from least to greatest) is concrete and immediate. God does "whatever he pleases" (Ps 115:3). Christ opens and no one shuts, shuts and no one opens" (Rev 3:7). "The purpose of the Lord will be established" (Prov 19:21).
Scripture, in attributing actions to God without mentioning any other causes, is not using a "primitive mode of speech" but is professing a faith in God's lordship over all history. Jesus tells us not to be anxious: "Your heavenly Father knows what you need. Seek first his kingdom and all these things shall be yours as well" (Mt 6:31-33).
Inviting Us to Cooperate (306-308)
God uses our cooperation. In his goodness, He gives us our existence and by our free will the opportunity to cooperate in his plan.
God even invites us to "subdue the earth and have dominion over it (Gen 1:26-28). He invites us to complete his work of creation. As knowing collaborators, we are "God's fellow workers" (1Cor 3:9).
We believe that God, the Creator (the first Cause) is always at work in us (the second cause). "For God is at work in you" (Phil 2:13). We can do nothing without God, especially gain eternal life. "Without a Creator, the creature vanishes" (Second Vatican Council).
Why is There Evil? (309)
Why does evil exist? This unavoidable and painful question can be adequately responded to only by the entire story of Christian faith, which includes the goodness of creation, the drama of sin, God's Covenants, the sendings of Jesus and the Spirit, and the founding of the Church. It includes the sacraments and the invitation to eternal life (which mysteriously can be rejected by anyone). Every aspect of Christian life is part of the answer to this question of evil.
A World "In a State of Journeying" (310)
God did not create a perfect world. In fact, God could have created a better world (St. Thomas Aquinas). God created this world "in a state of journeying." The more perfect exists alongside the less perfect. Nature has both constructive and destructive forces. Physical good will always be mixed with physical evil until creation reaches perfection.
Moral Evil (311)
Angels and men can freely choose to go astray. God never causes moral evil, either directly or indirectly. He permits moral evil because he respects man's freedom and knows how to draw good out of evil. "We know that in everything, God works for good for those who love him" (Rom 8:28). "God would never allow any evil if he could not cause good to emerge from it" (St. Augustine).
Good from Evil (312-314)
It takes time to see how God draws good from a moral evil. After being sold into slavery, Joseph told his brothers, "It was not you who sent me here, but God. You meant evil, but God meant it for good" (Gen 45:8, 50:20). God used Jesus' death (the greatest moral evil) for our redemption. Nevertheless, evil never becomes a good.
The saints witness to God drawing good out of evil. "Some rebel against what happens to them but God does nothing without the salvation of man in mind" (St. Catherine of Siena). "Nothing can come but that God wills" (St. Thomas More). "The Lord showed me that all manner of things shall be well" (Julian of Norwich).
Because we have only partial knowledge, many aspects of God's providence are hidden from us.
Heaven and Earth (325-327)
God is the "Creator of heaven and earth" (Apostles Creed). He created "all that is, seen and unseen" (Nicene Creed).
"Heaven and earth" means creation in its entirety. It shows the bond and the distinction between earth and heaven. "Earth" is the world of men. "Heaven" designates either the firmament, God's place of final glory, or the place where saints and angels live.
"From the beginning God made at once, out of nothing, both the spiritual (angels) and corporeal (earth) and, after that, God made the human creature who shares in both orders of spirit and body (Fourth Lateran Council).
Scripture and Tradition teach the existence of spiritual, non-corporeal beings (angels). Angel is the name of their office (what they do) and spirit is the name of their nature (what they are). While seeing the face of God, they also are his messengers who "hearken to the voice of his Word" (St. Augustine). Angels are personal, immortal, spiritual beings who have intelligence and will. By their glory, they surpass all visible creatures.
With Christ (331)
Christ is the center of the angelic world because "in him all things were created in heaven and on earth, visible and invisible" (Col 1:16). The angels are messengers of his saving plan. "Are they not all ministers sent forth to serve?" (Heb 1:14).
Activity in Scripture (332-333)
Angels have been active from the beginning. In Genesis, they closed the earthly paradise (3:24), saved Hagar and her son (21:17), and kept Abraham from killing Isaac (22:11). Later in Scripture, they led God's people, announced births, and assisted the prophets.
The angel Gabriel announced the birth of John the Baptist and the birth of Jesus (Lk 1:11-26). Angels announced Jesus' birth to shepherds (Lk 2:14), protected him in infancy (Mt 1:20; 2:13), served him in the desert (Mk 1:13), and strengthened him in the garden (Lk 22:43). Angels witnessed to Christ at the tomb and at his Ascension. They will also announce Jesus' return to judge mankind (Mt 24:31).
Their Work Now (334-336)
The Church benefits from the help of angels. At funerals, the angels are asked to lead the deceased into Paradise. All believers have a guardian angel who watches them from conception to death. Angels surround all human life with their care.