Part 2: Angels
All things that exist only do so in God. God, who is the Father, the Son, and the Holy Spirit, is the eternal, Supreme Being and Creator of all things visible and invisible. All that he has created expresses something of His eternal glory – including those creatures that are invisible. The invisible, living creatures of God are what we know as angels.
In the glossary of the Catechism of the Catholic Church, an “angel” is defined as: “A spiritual, personal, and immortal creature, with intelligence and free will, who glorifies God without ceasing and who serves God as a messenger of his saving plan.” This definition has several notable points: first – that angels are called “spiritual” beings speaks to the truth that angels are invisible by nature. While it is popular (and honestly very helpful) that we depict angels as pure white “human-looking” creatures who have wings, the truth is that angels do not have bodily form – as they are pure spirits. Spiritual as they are, the definition also calls them “personal…. with intelligence and free will.” That is to say that just as we human beings are “persons” who are capable of relating to others and who have intelligence and free will to choose the good, so too are angels endowed with these capacities. That angels are “immortal” speaks to the truth that they will never not be (once created, they will remain in existence forever). In other words, every angel did not exist prior to being created;
once created, every angel remains forever. Finally, angels glorify God and serve as His messengers – pointing to their true way of life and “function,” as it is, in serving God.
All of the angels are placed within the ranks of “choirs” of angels – each one created according to God’s designs for a particular purpose in giving Him glory and serving as his messengers. Within these choirs are the “guardian angels,” whom God wills to create for each human being at the moment that each one of us is conceived, to protect us from harm. In addition to these angels, other angels (like St. Michael the Archangel) are created with the particular purpose to aid us and protect us on our life journey toward heaven. Angels that remain faithful to God are always looking upon God (as Jesus tells us in Matthew 18:10 in particular reference to the guardian angels).
Please know: ALL of the angels were created good. However, some angels did not remain faithful to God in their call to serve – and in turning away from Him, these “bad” angels seek to tempt us away from God to commit sins and to be divided from God forever. It is these “bad angels,” the first of whom we refer to as the devil or Satan, who in their own free will have forsaken God and who desire to divide and destroy all that is good – tempting God’s human children away from Him toward accepting eternal separation from Him (what is called “hell”).
It is noteworthy that in their invisible nature, the angels always remain near to us. In addition to our guardian angels and the other angels who are present among us to guide us and protect us, there are angels who are present to guard and protect that which is holy – such as angels that are present to the Eucharist – during Mass, during times of Eucharistic Exposition, and when reserved in the tabernacle.
Thus, among and hidden within all that is visible are the angels who are invisible – many who serve God in giving Him glory and in aiding us in journeying toward God.
For further reading: In the Catechism of the Catholic Church, paragraphs 325-336 (along with summary paragraphs 350-352) give brief but complete treatment on angels.