The persecutions that started in the first century continued in the second. The Emperors Trajan (98-117), Hadrian (117-138) and Marcus Aurelius (168-180) picked up where Nero and Domition left off, persecuting Christians as far south as Vienne and as far east as Lyons, France. Whenever some sort of disaster, such as the plague, fell upon a city, the citizens of that city blamed the Christians, claiming that they were being punished because Christians refused to pay the gods homage.
This century also saw a number of Christian writings appear in the form of personal letters, apologetics and philosophy. The authors of such works included: St. Ignatius, Bishop of Antioch, who wrote seven letters encouraging Christian communities to practice their faith. Justin Martyr (100-165), who wrote about Christianity from a philosophical standpoint, is considered the first Christian philosopher. Tertullian (155-240) was a North African layman who wrote a number of treatises defending the faith. And lastly, there was St. Iranaeus, Bishop of Lyons (130-200), who wrote a very important work entitled Against the Heresies (189-190). In this work Iranaeus developed a creed, established a theology of apostolic succession and gave the Church of Rome preeminence over other Christian churches. His writing and theology contributed greatly to the doctrine of the early Church.
Against the Heresies did not only help with the development of Christian doctrine, but was used to help combat a growing heresy called "gnosticism". The Gnostics, led by a man named Marcion, believed that the material world was completely opposed to the spiritual world and that two gods existed - the god of the Old Testament who was mean and vengeful and the god of the New Testament who was loving and merciful. Marcion's theology eventually led him to develop his own version of the Bible.
At the close of this century the Church tackled the issue of when Easter should be celebrated. Unfortunately, the churches of the West celebrated Easter the week after the Jewish Passover while the churches of the East celebrated Easter on the Passover. To change this, Pope Victor I (189-198) used his authority and reminded the Eastern churches that the celebration of Easter on the Sunday after the Passover came directly from the Apostles, Peter and Paul. Though it took some time, the churches of the East eventually changed their calendar and began celebrating Easter on the same Sunday as the Western Church.
As the Church in Rome was beginning to emerge as the principal see diocese within Christianity, the hierarchical structure of the local Church was beginning to reflect the structure we have in place today. The bishop was head of the local church, while priests and deacons assisted him in caring for the spiritual and temporal needs of the people.