Many people believe that a powerful spirit made the world and everything in it.
When people pray they ask this spirit for help and love.
Groups of people share what they believe.
These groups are called religions.
There are different groups and different ways of believing.
One religion is Christianity.
People who follow it are Christians.
Their holy book is the Bible.
Christianity is named after Jesus Christ. There are different Christian religions, but they all believe that there is one god, and that his son, Jesus Christ, came to earth in human form and taught people how to live a good life, performed miracles and died to forgive the sins of humans.
An ancient stained glass window of the Last Supper - the last meal Jesus Christ shared with his closest followers just before his death. ©Getty Images
Three days after his death, Jesus rose again and forty days later eleven of his closest followers saw him rise up into the clouds. Christians believe that this was to teach people that there is a life after death - in beautiful place with God if you live a good life or in a terrible place if you don't.
People speak to God through prayer. The cross is one symbol of Christianity because Christ died on a cross. ©Getty Images
Christians speak with their god through prayer. The bible says that Jesus taught his followers how to pray, and to call God 'Father'.
There are some groups of Christians who pray directly to God, but they can also pray to a saint or saints asking them to speak to God on their behalf.
A saint is a Christian who has led a particularly good life, and who has made miracles happen after their death. After two miracles, which are usually people cured of terrible illness after they have prayed to that person, the process of becoming a saint begins. The declaration of their sainthood is called canonisation. Some Christian groups also pray to Mary, the mother of Jesus, to ask for her help by speaking to her son.
Baptism of a baby: holy water is dripped onto the baby's head as special prayers are said to welcome the baby toChristianity. ©Getty Images
Christians believe that to become a Christian, one has to be baptised, either as a baby or an adult. This is an outward sign that that person has made a commitment to the teachings of Jesus.
The spiritual leaders, those who give sacraments, conduct the rituals and teach the beliefs, are priests or ministers: their titles and rules of living are different according to their religion. A priest or minister can be promoted to bishop, archbishop, or in some religions to cardinal. In the Roman Catholic religion, a cardinal is elected by other cardinals to be the Pope, or leader of the religion, and in the Eastern Orthodox church the leader is the Patriarch. In some Christian religions the priest or minister can be a woman. Some Christian religions have nuns, women who have dedicated their lives to Jesus and to doing good works.
Russian cathedrals are famous for their very decorative 'onion' roofs. ©Getty Images
The place of worship for Christians is a church. A very large and important church is a cathedral.
The main regular gathering of Christians in a church is to celebrate the Eucharist, or Holy Communion. The name of it and the way this is celebrated is different in the different Christian religions, but the origin is the same: it is based on the actions of Jesus at the last meal he shared with his closest followers (the Apostles or Disciples) before his death. He asked them to continue to share bread and wine as they did at this Last Supper in order to remember him. Different Christian religions have different beliefs about the meaning of this instruction.
There are different rituals celebrated in each Christian religion. One of these is confirmation, and confirms the commitment to Jesus that was made by baptism. In most religions it is performed when a person is old enough to understand what that commitment is and what they are promising. It confirms that a person is now fully a Christian.
The Bible is the holy book for Christians.
Both Christmas and Easter are special festivals of the Church, one celebrating the birth of Christ and other his death on a cross and his resurrection three days later. Most Christians observe Lent in the six weeks before Easter, a time of prayer and thoughtfulness, of giving up luxuries. Ash Wednesday is the first day of Lent. The day before that is Shrove Tuesday, traditionally the last good time and good food before the serious, holy time of Lent.
A 'Golden Rule' shared by many religions
Many world religions share a similar teaching to live by. For example:
Christianity: treat others in the way you like to be treated;
Buddhism: do good things and good things will happen to you;
Hinduism: treat others as you like to be treated;
Islam: treat others as you would like to be treated;
Judaism: what treatment you hate, don’t do to anyone else;
Native American: live in harmony, for we are all related.
Read more about Christianity:
http://www.bbc.co.uk/religion/religions/christianity/