Arians
heretics who claimed that Jesus was less than divine (p. 90)
Athanasius
the young deacon who argued against the Arian heresy at the Council at Nicaea in 325 (p. 91)
Constantine
Roman emperor who reigned from 312 to 337; in 313 he issued the Edict of Milan, granting religious tolerance throughout the Roman Empire and giving Christians the freedom to worship openly. He became a Christian himself late in life; His mother was Saint Helena. (p. 88)
Council at Chalcedon
called by Pope Saint Leo the Great in 451; considered the greatest of the first four ecumenical councils; at it the bishops affirmed the teaching that Jesus is one person with two natures, divine and human, and that these two natures do not interfere with or compromise each other (p. 91)
Council at Constantinople
an important early ecumenical council called by the Emperor Theodosius I and held in 381 in the city of Constantinople (modern-day Istanbul); at it the bishops repeated the teaching of the Council at Nicaea and reiterated the truth that the Holy Spirit, like Jesus, is also fully divine. Our salvation is the work of one God, but that God exists in three divine Persons, the Father, the Son, and the Holy Spirit. (p. 91)
Council at Ephesus
ecumenical council called in 431 to deal with the heresy of Nestorius, who claimed that Jesus was really two different persons, one human and one divine, and that Mary was not the Mother of God but only mother of the human Jesus (p. 91)
Council at nicaea
a council of all the bishops of the Church, called by the Emperor Constantine and held in 325 in the city of Nicaea, in modern-day Turkey; the first ecumenical council. At it the young deacon Athanasius argued against the Arian heresy. (p. 91)
Decius
Roman emperor who persecuted Christians during his reign, from 249 to 251 (p. 88)
Diocletian
Roman emperor who persecuted Christians during his reign, from 284 to 305 (p. 88)
Docetists
heretics who claimed that Jesus only pretended to be human and so didn't really suffer on the cross (p. 90)
Donatists
heretics who claimed that only "saints" can belong to the Church (p. 90)
ecumenical council
a council that brings together the bishops of the whole world with the bishop of Rome, the pope. The word ecumenical comes from Greek and means "of the whole world." Over the whole history of the Church, there have been twenty-one ecumenical councils; the first was the Council held at Nicaea in 325; the most recent was the Second Vatican Council, held in Rome in 1962-1965. (p. 91)
Edict of Milan
edict issued by the Roman Emperor Constantine in 313, giving Christians the freedom to worship openly (p. 88)
Albert Einstein
(1879-1955) German-born physicist; considered one of the greatest scientists of the 20th century (p. 87)
Fathers of the Church
scholars and writers who helped to explain and hand on the Christian message during the first centuries of the Church and whose work contributed in important ways to the understanding of the Christian faith and to the life and growth of the Church (p. 90)
Gnostics
heretics who claimed that God's real revelation was available only as secret knowledge to a select few (p. 90)
Great Persecution
persecution of Christians that began in 303 under the Roman Emperor Diocletian and continued until 311 under his successor, Galerius (p. 88)
Manichees
heretics who claimed that the material world is evil and that it was created by an evil spirit (p. 90)
Marcionites
heretics who followed Marcion, a scholar who tried to convince the Church to exclude the Old Testament from the Bible (p. 90)
Monophysites
heretics who claimed that Jesus was only divine and thus not fully human (p. 90)
Origen
(c. 185-254) a Father of the Church; he studied and explained Scripture. (p. 90)
Saint Ambrose of Milan
(c. 340-397) Doctor of the Church; bishop of the Italian city of Milan; defender of Christ's divinity against the Arian heresy. Among the people he converted and baptized was Saint Augustine of Hippo (p. 92)
Saint Helena
(250-330) mother of the Roman Emperor Constantine and a convert to Christianity; remembered for helping to found churches and serving the poor (p. 85)
Saint Jermoe
(c. 347-420) a Father of the Church; he translated the Bible into Latin from Hebrew and Greek. (p. 90)
Saint John Chrysostom
(c. 347-407) a Father of the Church; a great preacher whose name means "golden-mouthed." (p. 90)
Tertullian
(c. 155-222) a Father of the Church; he developed a vocabulary of terms with which to describe the faith. (p. 90)
Theodosius I
Roman emperor who, during his reign (379-395), made Christianity the official religion of the Roman Empire (p. 88)