The Great Heresies

What heresy is

"Heresy" is often misused. The Catechism distinguishes incredulity (neglecting or refusing revealed truth), heresy (the obstinate post-baptismal denial or doubt of a truth that must be believed with divine and Catholic faith), apostasy (total repudiation of the faith) and schism (refusing submission to the pope or communion with the Church) (CCC 2089).

• One must refuse correction. Someone open to correction, or unaware he contradicts Church teaching, is not a heretic.
• One must be baptized. Groups without (valid) baptism, such as Muslims or Jehovah's Witnesses, are separate religions, not heresies.
• The matter must be revealed by God and solemnly defined, such as the Trinity, the Incarnation, the Real Presence, the sacrifice of the Mass, papal infallibility, or the Immaculate Conception and Assumption.

Major heresies

• The Circumcisers (1st century) taught that one must be circumcised, becoming a Jew, to be saved (Acts 15:1). God showed Peter in Acts 10 that Gentiles may be baptized without circumcision, and Paul defended this in Romans and Galatians.
• Gnosticism (1st–2nd centuries) held that matter is evil, contradicting Genesis 1:31 and denying the Incarnation: Christ only seemed to be a man. Some called the Old Testament God an evil deity and taught many divine "aeons," the lowest being Christ.
• Montanism (late 2nd century): Montanus preached penance and miraculous gifts, but set his teaching above the Church's, predicted Christ's return in his home town, and claimed to be, or speak for, the Paraclete.
• Sabellianism (early 3rd century): Father and Son are not distinct persons but aspects of one person; the Trinity exists only in God's relation to man.
• Arianism (4th century): Christ is a creature. Condemned at Nicaea (325), which defined Christ's divinity, and Constantinople (381), which defined the Spirit's; together they gave us the Nicene Creed.
• Pelagianism (5th century) denied original sin and held that man, born morally neutral, can reach heaven by his own powers, grace merely making it easier.
• Semi-Pelagianism (5th century), after Augustine refuted Pelagius, held that we can reach out to God without grace, keep grace by our own effort, and have some claim to grace by natural effort.
• Nestorianism (5th century): Nestorius denied Mary the title Theotokos ("God-bearer"), which would split Christ into two persons. The Council of Ephesus (431) defined that Mary is the Mother of God, because the one she carried was God incarnate. Nestorius may not have held the heresy, and the Assyrian Church of the East has signed an orthodox joint declaration with the Catholic Church.
• Monophysitism (5th century), led by Eutyches, went to the other extreme: Christ has one fused nature, denying his full humanity and full divinity.
• Iconoclasm (7th–8th centuries) called images of Christ and the saints sinful, though God commanded religious images (Exodus 25:18-20; 1 Chronicles 28:18-19), including a symbol of Christ (cf. Numbers 21:8-9 with John 3:14).
• Catharism (11th century): an evil god made the world. The Albigensians taught the body was evil, so having children was among the greatest evils; marriage was forbidden but fornication permitted, alongside severe fasts.
• Protestantism (16th century), with wide doctrinal variety but nearly all holding sola scriptura and sola fide. Its doctrine of private judgment, which denies the Church's infallible authority, is rejected by 2 Peter 1:20 and has produced thousands of denominations.
• Jansenism (17th century): Jansenius redefined grace; his followers held Christ died only for the elect. Pope Innocent X condemned it in 1653.

The promise

Heresies have even been started by Church leaders, later corrected by councils and popes. But Christ promised the gates of hell would not prevail against the Church (Matthew 16:18), which is "the pillar and foundation of truth" (1 Timothy 3:15).