Fathers & theologians

Father, Son and Holy Spirit

Catechism 232–267

The fall and original sin

Catechism 385–421

The Word made flesh

Catechism 456–483

Christ among the dead

Catechism 631–637

The Holy Spirit in salvation history

Catechism 683–747

What sacraments are

Catechism 1113–1134

The Eucharist and the Mass

Catechism 1322–1419

Grace, justification and holiness

Catechism 1987–2029

Reading historical sources

Theological schools

East-West theological comparison

Study Ambrose of Milan

Study Athanasius of Alexandria

Study Augustine of Hippo

Study Basil of Caesarea (Basil the Great)

Study Clement of Alexandria

Study Clement of Rome

Study Cyprian of Carthage

Study Cyril of Alexandria

Study Cyril of Jerusalem

Study Eusebius of Caesarea

Study Gregory of Nazianzus (Gregory the Theologian)

Study Gregory of Nyssa

Study Hermas

Study Ignatius of Antioch

Study Irenaeus of Lyons

Study Jerome

Study John Chrysostom

Study Justin Martyr

Study Origen

Study Polycarp of Smyrna

Study Gregory the Great

Study Leo the Great

Study Tertullian