The Church was born from Christ, who gave His life on the cross, and was revealed to the world at Pentecost, when the Holy Spirit came upon Mary and the apostles in tongues of fire. Peter preached, and about three thousand people were baptized that day. Church history had begun.
The first Christians in Jerusalem met in homes to hear the apostles' teaching, share their goods, break bread and pray. At first nearly all of them were Jewish, and they still prayed in the Temple. Outsiders noticed how they loved one another.
Soon a big question arose: did Gentiles (people who were not Jewish) have to keep all the laws of Moses to become Christians? Around the year 50, the apostles and elders met in Jerusalem with Peter and James. Guided by the Holy Spirit, they decided that Gentiles did not. This Council of Jerusalem was the first of many Church councils.
Paul, once a persecutor, became the apostle to the Gentiles. On long journeys by land and sea, he founded churches across what is now Turkey and Greece and wrote letters to guide them. Thirteen New Testament letters bear his name.
Peter, the rock on whom Christ built His Church, went to Rome, the capital of the empire. There, in the 60s AD, under Emperor Nero, both Peter and Paul were martyred. Saint Peter's Basilica stands over Peter's tomb, and every Pope succeeds him as Bishop of Rome.
Before they died, the apostles laid hands on men to carry on their work. These were the first bishops. This unbroken line, called apostolic succession, links today's bishops to the apostles, so the Church we belong to is the same Church Jesus founded.