One God, three persons
Most Christians believe in one God, Father, Son and Holy Spirit, and that in Jesus God became human: he lived among us, died on the cross and rose again.
Χριστιανισμός & Christianitas
Christianity
Christianity is the faith of those who follow Jesus of Nazareth, believing him to be the Son of God, the Christ.
It began among his Jewish followers in the first century.
Around 2.3 billion people are Christian today, the largest faith in the world.
At its heart
What Christianity holds
The Bible
The Old Testament, the scriptures Jesus himself read, and the New: four Gospels of his life, the Acts of the Apostles, letters and Revelation.
Churches differ on a few books, so a Protestant Bible has 66, a Catholic one 73, an Orthodox one more.
Love of God and neighbour
Jesus summed up the law in two commandments, to love God and to love your neighbour as yourself.
He taught in parables and gave his followers a prayer, the Lord’s Prayer.
Branches
In ActivePray
Christianity has three great families, Catholic, Orthodox and Protestant, with many churches within each, and the ancient Oriental Orthodox churches besides.
ActivePray keeps three.
- Prayers
Morning Prayers, the Hours, Vespers and the Prayers before Sleep, each with its Greek name.
Vespers begins the liturgical day at sunset; the others are at hours you set.
- Calendar
- The Great Feasts and the fasting seasons, with Pascha, on the New or the Old Calendar.
- Scripture
- The Bible in the Orthodox canon, 76 books with the Anagignoskomena, the Psalter of 151 psalms, and prayers for meals, illness and grief.
- Before prayer
- Standing before the icons, facing east, with the sign of the cross, and forgiving whoever is owed it.
- Your choices
- The New or the Old Calendar, and the hours of the morning prayers, the Hours and the prayers before sleep.
- Prayers
The Liturgy of the Hours, each with its Latin name: the Office of Readings, Morning, Daytime, Evening and Night Prayer, at hours you choose.
The Regina Caeli in Eastertide.
- Calendar
- The Roman calendar: its seasons, its solemnities and feasts, and the colour of the day.
- Scripture
- The Bible in the Catholic canon, 73 books, the Rosary with its four sets of mysteries, and prayers for meals, illness and grief.
- Before prayer
- The sign of the cross, with holy water if you keep it by the door, a moment in God’s presence, and an examination of conscience.
- Your choices
- All five hours, or Morning and Evening Prayer, the two hinges of the day, with Night Prayer; and the hour of each.
- Prayers
- The Daily Office: Morning Prayer, Noonday Prayer, Evening Prayer and Compline, or a single quiet time, at hours you choose.
- Calendar
- The church year, its seasons and its holy days.
- Scripture
- The Bible, 66 books, the Psalter, and prayers for meals, illness and grief.
- Before prayer
- Stillness, and an honest confession.
- Your choices
- Four offices or one quiet time, and the hour of each.
A short history
How it came to be
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c. 30 CE
Jesus of Nazareth
A Jewish teacher in Galilee and Judea under Roman rule, who gathered disciples, healed and taught, and was crucified in Jerusalem under Pontius Pilate.
His followers proclaimed that he had risen.
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First century
The first churches
The apostles carried the message across the Roman Empire.
Paul’s letters, written in the 50s, are among the earliest Christian writings.
Christians met on Sunday, the day of the resurrection.
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313–325
Freedom and a creed
In 313 the Edict of Milan granted Christians freedom of worship across the empire.
In 325 the Council of Nicaea set out the faith in a creed which, as expanded at Constantinople in 381, is still said in churches today.
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1054
East and West
The Greek-speaking East and the Latin West had grown apart, and the Church divided between Constantinople and Rome: the Orthodox and the Catholic churches.
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1517
The Reformation
Martin Luther’s ninety-five theses began a call back to scripture and to grace through faith, and from it came the Protestant churches.
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Today
A world faith
Carried to every continent, it is prayed in the languages of the world, and the Bible has been translated, at least in part, into more than four thousand of them.
The day and the week
How it is prayed
Sunday
The Lord’s Day: worship together, the scriptures read and preached, and at its centre the bread and wine of the Last Supper, called the Mass, the Divine Liturgy or the Lord’s Supper.
The hours of prayer
Since the early Church Christians have prayed at set hours, morning and evening above all.
The Liturgy of the Hours, the Orthodox prayer rule and the Daily Office carry that on.
Small prayers
Grace before meals, prayers before sleep, the Lord’s Prayer, the Rosary, the Jesus Prayer: the short prayers that hold a day together.
The year
Its holy days
Advent and Christmas
In the West, the weeks of Advent; in the East, a forty-day fast.
Then the birth of Jesus on 25 December, which churches on the Julian calendar keep on what is now 7 January.
Lent and Easter
Forty days of prayer, fasting and giving, then Holy Week and Easter, the resurrection, the oldest and greatest feast.
The Orthodox call it Pascha, often on a different date.
Pentecost
Fifty days after Easter, the Holy Spirit coming upon the apostles: often called the birthday of the Church.
Feasts and fasts
Feasts of Mary and the saints through the year; Wednesdays and Fridays as fast days in the Orthodox Church, and Fridays as days of penance in the Catholic.
See everything the app does“Do not be anxious about anything, but in every situation, by prayer and petition, with thanksgiving, present your requests to God.
And the peace of God, which transcends all understanding, will guard your hearts and your minds in Christ Jesus.”
Philippians 4:6–7 (NIV)
Figures: Pew Research Center, 2025, counting 2020; Bible translations from Wycliffe Global Alliance, 2025.