may bring unused cholesterol back to
the liver to be broken down before it is
removed from the body.
The liver makes most of the cholesterol
the body needs. However, because cholesterol
is in animal cells, when people
eat animal products they are getting
extra cholesterol. When extra cholesterol
hardens, blood vessels become narrower.
It then becomes harder for the heart to
pump blood through the vessels. This
can cause such problems as heart attacks
or strokes.
People can lower their cholesterol levels
by exercising, maintaining a healthy
weight, and eating healthy foods.
Doctors may recommend that people
with high cholesterol eat less red meat,
egg yolks, cheese, butter, and liver.
These are major sources of cholesterol.
Because fruits and vegetables do not
contain any cholesterol, doctors often
advise people to eat more of these types
of foods.
When there is no cholesterol built up in
blood vessels, blood can easily flow
through the vessels’ openings.
Plants, and
foods that
come from
plants, such as
olive oil,
canola oil, or
corn oil, do
not contain
cholesterol.
When cholesterol builds up in blood vessels,
it is difficult for blood to flow through
the narrow openings in the vessels.
BRITANNICA STUDENT ENCYCLOPEDIA Cholesterol 111
Christianity
With some 2 billion followers, Christianity
is the world’s most widespread
religion. Christianity is based on the life,
death, and teachings of Jesus of Nazareth.
The religion has three main
branches—Roman Catholicism, Eastern
Orthodoxy, and Protestantism.
Beliefs
Central to Christianity is the belief that
Jesus is the Christ, or chosen one, whom
God sent to the world to save humans.
Christians maintain that Jesus had to
suffer, die, and be resurrected (raised
from the dead) to make up for people’s
sins. Christians view Jesus’ new life after
death as hope that they too may be
granted everlasting life.
Christians also believe in the Trinity.
The Trinity (meaning the three) is the
idea that three figures are united in one
God: God the Father, God the Son
(Jesus), and God the Holy Spirit. The
Holy Spirit is thought of as a helper sent
to guide and teach humans.
The sacred scripture of Christianity is
the Bible. It has two books—the Old
Testament (or Hebrew Bible) and the
New Testament, which tells the story of
Jesus.
Practices
At the core of Christian living is love for
God above all things. Christianity also
tells people to love one another and to
be forgiving, humble, and kind.
Some Important Christian Holidays
Holiday Meaning Date
Advent period of preparation for Christmas begins on the Sunday nearest to
November 30
Christmas celebration of Jesus’ birth December 25
Epiphany celebration of the visit by the Magi, January 6
or Wise Men, to the infant Jesus
Lent period of preparation for Easter begins 40 days, not including Sundays,
before Easter
Easter celebration of Jesus’ rise from the first Sunday after the first full moon
dead after the spring equinox (March 21)
Worshippers in a Roman Catholic
church face the altar, which is
heavily decorated. Roman
Catholic churches often have
more statues and other decorations
than Protestant churches.
112 Christianity BRITANNICA STUDENT ENCYCLOPEDIA
Many Christians regularly attend church
services, with Sunday being the most
common day of worship. Services usually
involve singing, Bible readings, and
a sermon, or a talk by a priest or minister.
In many churches, services include a
ceremony called Communion. In this
ceremony, members eat bread and drink
wine in memory of the final meal Jesus
had with his followers.
History
Jesus and Followers
Christianity grew out of Judaism in the
Middle East. In about AD 29 a Jew
named Jesus began to preach in Galilee.
He attracted many followers because of
his healing powers and his religious
teachings. But people in power feared
that he might lead an uprising, and they
put him to death. The Bible holds that
Jesus rose from the dead three days after
being put to death, spent 40 days on
Earth, and then was taken up to heaven.
For many years, Jesus’ followers continued
to practice religion in the same way
as Jews, except they believed that Jesus
was a savior sent from God. In the 1st
century AD a missionary named Paul
helped separate Christianity and Judaism
into two distinct religions.
Spread of Christianity
To help spread Jesus’ teachings, some
early Christians wrote about him. Writings
by four men—Matthew, Mark,
Luke, and John—were chosen as the
standard account of Jesus’ life and teaching.
These four narratives now form part
of the New Testament.
In the early days of the church, the
Roman Empire controlled most of the
Mediterranean region. Life was difficult
and dangerous for Christians living
within the empire. They were treated
harshly for their beliefs. In AD 312, however,
the Roman emperor converted to
Christianity. By the end of the 300s,
Christianity was the empire’s official
religion. This power helped secure
Christianity’s place in the world.
Some Protestant Christian churches attract
large numbers of people.
Greek Orthodox Christian priests and worshippers
gather for a service in Bethlehem.
