What does the Church teach about the devil?
The short answer
The Church teaches that Satan is real: a fallen angel who, with other demons, freely and irrevocably rejected God. He tempts and deceives, but he is a creature, not God's equal, and his power is limited. Christ has already defeated him, and through prayer and the sacraments believers can resist him.
A fallen angel
God created the angels good. Some, led by Satan, freely chose to reject God, and their choice is irrevocable (CCC 391-393). Jesus calls the devil "a liar and the father of lies" (John 8:44). Satan means "adversary"; devil comes from the Greek diabolos, "slanderer."
Real, but not all-powerful
The devil is not an evil god equal to the good God. He is a creature. "The power of Satan is, nonetheless, not infinite… he cannot prevent the building up of God's reign" (CCC 395). Christ's death and Resurrection have already won the decisive victory.
How the devil works
Ordinarily, not through dramatic possession, but through temptation: lies, discouragement, pride, division and the suggestion that sin does not matter. "Your opponent the devil is prowling around like a roaring lion looking for [someone] to devour. Resist him, steadfast in faith" (1 Peter 5:8-9).
Our protection
- Prayer, especially the Our Father: "deliver us from evil" (CCC 2851).
- The sacraments, above all Confession and the Eucharist.
- Scripture — Jesus answered every temptation in the desert with God's Word.
- Sacramentals such as holy water, and the Prayer to Saint Michael.
Possession and exorcism
Genuine possession is rare. The Church carefully distinguishes it from mental illness, and only a priest authorized by the bishop may perform a major exorcism (CCC 1673). Anyone troubled should first speak with a priest — and seek medical help where appropriate.