Catholicism

• The Bible (Catholic canon) compiled 4th century CE from far older material

  Includes seven deuterocanonical books that most Protestant Bibles omit — a real and consequential difference. Catholicism reads it alongside tradition rather than as the sole authority.

• The Nicene Creed 325 CE, revised 381

  The short statement of belief hammered out at two councils and recited at Mass every Sunday. It is the most compact summary of what the Church actually claims, and every clause in it was fought over.

• Catechism of the Catholic Church 1992

  The modern reference work laying out belief, sacraments, moral teaching and prayer in one indexed volume. Useful precisely because it lets you check what the Church officially says rather than what people assume it says.

• c. 6–4 BCE – 30/33 CELife of Jesus of NazarethLife of Jesus, the central figure of Christianity, crucified in Roman Judea c. 30–33 CE.
• c. 30 CEJerusalem church formsAfter the crucifixion, apostles led by Peter and James form the nucleus of the earliest Christian community, initially a sect within Judaism practicing communal living.
• c. 46–60 CEPaul's missions and the Council of JerusalemPaul's journeys plant churches across Asia Minor and Greece; the first Christian council in Jerusalem opens the faith to Gentiles without full Jewish law observance.
• 64 CENero's persecutionAfter the Great Fire of Rome, Christians are scapegoated and brutally executed — the first imperial-level targeting of the new faith.
• c. 70 CEGospel of Mark writtenThe earliest gospel is composed; Matthew and Luke follow c. 80–90, John c. 90–100.
• 249–251 CEDecian persecutionFirst empire-wide persecution: edicts require all citizens to certify sacrifices to the gods and emperor, producing mass lapses, confiscations, and martyrdoms.
• 303–311 CEThe Great PersecutionDiocletian and Galerius demolish churches, burn scriptures, and demand universal sacrifice; its failure — capped by Galerius's 311 toleration edict — demonstrates Christianity's resilience.
• 313 CEEdict of MilanConstantine and Licinius decree religious toleration across the Roman Empire, legalizing Christianity.
• 325 CECouncil of NicaeaFirst ecumenical council establishes the Nicene Creed and fixes the date of Easter, defining orthodox Christology against Arianism.
• c. 350 CECodex SinaiticusOldest surviving complete Christian Bible, in Greek including the Septuagint.

Understand the oldest continuously running institution in the West from the inside.

1. Module 1

   Original Sin and Grace

   You understand the founding diagnosis: human beings arrive damaged and cannot repair themselves, which is why grace has to come from outside.

   Do: Write down one flaw you have repeatedly resolved to fix and repeatedly failed to fix.

2. Module 2

   The Seven Sacraments

   You understand the sacramental logic — that physical acts with water, oil, bread and words are held to actually do something, not merely symbolise it.

   Do: Attend a Mass and watch the Eucharistic prayer specifically, noting where the room's attention changes.

3. Module 3

   Hierarchy and Authority

   You understand how the structure runs from parish priest to bishop to Pope, and what the narrow doctrine of papal infallibility does and does not cover.

   Do: Look up how many times papal infallibility has been formally invoked, and be surprised.

4. Module 4

   Confession and Conscience

   You understand why the Church built an external, spoken, regular audit of conscience — and why people who dislike the theology often miss the mechanism.

   Do: Do a written examination of conscience for one week and notice what changes when it must be said aloud, even hypothetically.

5. Module 5

   Social Teaching and Scandal

   You understand both the body of Catholic social teaching on labour, poverty and dignity, and the abuse crisis that has defined the Church's modern credibility.

   Do: Read one papal encyclical on labour or the environment alongside one serious report on the abuse crisis.

• Lent and the Easter Triduum forty days before Easter, climaxing in late March or April

  Fasting, abstinence and almsgiving leading into the three days from Holy Thursday to Easter — the most intense liturgy of the Catholic year.

• Advent and Christmas four weeks before 25 December

  A season of waiting with its own colours, music and restraint, ending in the Midnight Mass most cultural Catholics still turn up for.

• Patronal feasts and processions varies by place

  Local saints' days that shut down whole towns in Spain, Italy, the Philippines and Latin America; the folk face of the institution.

Catholicism's defenders say a hierarchy that never leaves you alone is what let it build hospitals, universities and continents of charity. Its critics say the same hierarchy is what let abuse be concealed for decades. Are those two facts separable, or the same fact?