Q: Does the Catholic Church teach the existence of a personal being known as Satan? I have heard some suggest that the devil is just a myth or a cosmic archetype rather than a conscious, intelligent being.

A: Yes, and that is just what he would like you to believe. Whenever possible he blinds people to his own reality. However, the Church, faithful to the teachings of its founder Jesus Christ, is very firm in proclaiming the existence of the devil.

Here is what the Catechism of the Catholic Church says:

391 Behind the disobedient choice of our first parents lurks a seductive voice, opposed to God, which makes them fall into death out of envy. [Cf. Gen 3:1-5; Wis 2:24] Scripture and the Church’s Tradition see in this being a fallen angel, called “Satan” or the “devil”. [Cf. Jn 8:44; Rev 12:9] The Church teaches that Satan was at first a good angel, made by God: “The devil and the other demons were indeed created naturally good by God, but they became evil by their own doing.” [Lateran Council IV (1215): DS 800]

394 Scripture witnesses to the disastrous influence of the one Jesus calls “a murderer from the beginning”, who would even try to divert Jesus from the mission received from his Father. [Jn 8:44; cf. Mt 4:1-11] “The reason the Son of God appeared was to destroy the works of the devil.” [I Jn 3:8] In its consequences the gravest of these works was the mendacious seduction that led man to disobey God.

395 The power of Satan is, nonetheless, not infinite. He is only a creature, powerful from the fact that he is pure spirit, but still a creature. He cannot prevent the building up of God’s reign. Although Satan may act in the world out of hatred for God and his kingdom in Christ Jesus, and although his action may cause grave injuries–of a spiritual nature and, indirectly, even of a physical nature–to each man and to society, the action is permitted by divine providence which with strength and gentleness guides human and cosmic history. It is a great mystery that providence should permit diabolical activity, but “we know that in everything God works for good with those who love him.” [Rom 8:28]

The Catechism thus teaches that the devil is a fallen angel. And lest anyone try to reduce the idea of an angel to a myth or a cosmic archetype, the Catechism is very specific in stating that

330 As purely spiritual creatures angels have intelligence and will: they are personal and immortal creatures, surpassing in perfection all visible creatures, as the splendor of their glory bears witness. [Cf. Pius XII, Humani generis: DS 3891; Lk 20:36; Dan 10:9- 12]

As beings with intelligence and will, angels–including the devil–are thus conscious, spiritual entities who count as true (though non-human) persons.