How did Christianity spread quickly through the Roman Empire?

Christianity spread fairly slowly at first and is estimated to have been followed by around ten per cent of the population of the Roman Empire by the time of mperor Constantine, after around three hundred years. It was Constantine wh began the rapid spread of Christianity.

Constantine gave the Church state patronage and massive financial support. He ensured that those of ambition knew that their career prospects would be improved by declaring themselves to be Christian. He also offered each Roman who converted a white garment, with twenty pieces of gold. The lower classes were encouraged by the example of the elite classes to become Christians, and the Church was permitted to distribute the state's food aid to the Roman poor, providing it the opportunity to proselytise. Constantine began the persecution of the pagan temples, continued with even greater intensity by his Christian sons and successors. Once Theodosius declared the public worship of the pagan gods illegal in 391 and even made it a crime to look at an idol that had been smashed by the Christian mobs, it was no longer safe to be a pagan in much of the empire, and Christianity spread very rapidly.
Christianity spread fairly slowly at first and is estimated to have been followed by around ten per cent of the population of the Roman Empire by the time of Emperor Constantine, after around three hundred years. It was Constantine wh began the rapid spread of Christianity.

Constantine gave the Church state patronage and massive financial support. He ensured that those of ambition knew that their career prospects would be improved by declaring themselves to be Christian. He also offered each Roman who converted a white garment, with twenty pieces of gold. The lower classes were encouraged by the example of the elite classes to become Christians, and the Church was permitted to distribute the state's food aid to the Roman poor, providing it the opportunity to proselytise.

Constantine began the persecution of the pagan temples, continued with even greater intensity by his Christian sons and successors. Once Theodosius declared the public worship of the pagan gods illegal in 391 and even made it a crime to look at an idol that had been smashed by the Christian mobs, it was no longer safe to be a pagan in much of the empire, and Christianity spread very rapidly.
Christianity spread throughout the Roman Empire in a series of steps.

We can start with the Day of Pentecost, the very first day of the Church, when Peter declared to the thousands gathered in Jerusalem for that festival that salvation, leading to eternal life, was available to all who repented of their sins and were baptised in the name of Jesus Christ. He told them that this promise was available to everyone, whether they were present that day, or in that place, or were far off in time or place. Three thousand became Christians on that day. They were drawn from a crowd of people who came from all over the Roman Empire, and from the Parthian (Persian) Empire as well.

A few years later, most of the early Christians fled from Jerusalem, since the authorities there were offended by the preaching of one of the Christian leaders, Stephen. One of the destinations of the fleeing Christians was the Syrian city of Antioch. It was in Antioch that Christianity began to be actively preached to non-Jews. This eventually led to the first organized missionary journey, conducted by Barnabas and Paul, and saw the Christian message go to Cyprus and then to southern Galatia, in Anatolia (modern Turkey). New churches were established in both regions. Further missionary journeys, by Paul and Silas, saw Christianity being spread in Greece and in the Roman province of Asia (also in Anatolia). Other missionaries took the Christian message to other places, such as Bithynia, Pontus and Cappadocia (also in Anatolia), and individual Christians certainly took the Christian message to Rome.

So, within a generation of the Church starting, Christianity had already gained a foothold in many provinces of the Roman Empire, and certainly in all the provinces of the eastern half of the Roman Empire.

The next two hundred years saw the Christian Church expand and grow from these early roots. We have very little information about how this happened, but we have a few precious fragments, such as the account of the persecution of Christians in two cities on the Rhone river (in modern France). This is discussed in the related question, shown below, "What caused the spread of Christianity to go north of the alps?"

In Bithynia (in north-western Anatolia), at the beginning of the second century, the Roman governor, Pliny, discovered that the old cults were being deserted, and Christianity was widespread amongst the ordinary people. He claimed he had been able to suppress the Christian cult, and to encourage the people to return to the old cults, through a widespread policy of torture and execution of those most intractable followers of the Christian religion. Emperor Trajan supported his actions, but warned against a policy of seeking out Christians too vigorously.

Meanwhile, supporters of the traditional religions, and particularly the philosophers, were becoming aware of the challenge posed by Christianity. They met it in various ways. The best known of these responses is the work, The True Word, written by a Platonic philosopher in the middle of the second century, and embedded in a rebuttal written by the Christian philosopher, Origen, in the middle of the third century.

Origen's influence is rather difficult to assess, however, it appears that most of the bishops of the provincial capitals in Anatolia in the second half of the third century were influenced by his writing and teaching.

We know less than we would like to know about Christianity in the second half of the third century. Yet we can discern that the influence of Origen's teaching probably saw Christianity gaining intellectual ascendancy in Greece, Anatolia and Syria / Palestine. It was also gaining a measure of popular support in those places as well as in Egypt.

This period was bracketed by the two great periods of persecution in the history of the Church. The first was launched by Emperor Decius in 250, and tried again by Emperor Valerian in 257. The second was launched by Emperor Diocletian in 303. It is difficult to avoid the conclusion that the Church in the eastern half of the Roman Empire grew enormously between these two horrendous events.

In the western half of the Roman Empire, the Church was also growing, but it does not appear to have reached anywhere near the strength and importance of the Church in the eastern half of the Roman Empire. However, Constantine's conversion to Christianity, which can be reasonably dated to 312, changed everything, with the Christianity's status in the western half of the Empire being changed from a mostly tolerated religion, and sometime persecuted religion, to a favoured religion. When Constantine became a Christian, he encouraged its spread.

In 313, the emperor in the eastern half of the Roman Empire, Licinius, joined with Constantine in publishing the Edict of Milan, which granted Christianity formal tolerance throughout the Roman Empire. These colleagues in the Empire were also rivals, and in 324 Constantine defeated Licinius, and began to rule the entire Roman Empire on his own. Christianity was then favoured throughout the whole of the Roman Empire, in both the west and the east.

Christianity was already on the move before Constantine took power; now with state support it grew from strength to strength. The great Christian historian, Eusebius, admitted that he believed that many conversions to Christianity were for the wrong reasons. On the other hand, we have sufficient evidence to show that the free spread of Christianity resulted in many genuine conversions, and more significantly for this topic, the gradual phasing out of the old cults as a central part of the people's lives, with the notable exception of Rome itself.

There is no doubt that a large measure of self-interest was involved in some conversions to Christianity. One can understand that this applied particularly to the curial class. These were the rich people who were required to fund basically all the civil functions of the state, and kept the cities operating. Initially, it was a simple change, since those members of the curial class who became Christian priests were no longer required to meet these obligations. This followed the previous practice of extending exemptions to those members of the curial class who took on other civic obligations, such as being priests of the traditional cults, taking responsibilities in the military, or becoming a senator. However, it was not really equivalent, and as a result, in 329, Constantine required bishops and clergy to be generous towards the poor. He also restricted the entry of the curial class into the priesthood.

Missionary activities within the Roman Empire continued during the fourth century, with most significant being the mission of Ulfilas to the Goths on the borders of the Roman Empire, which eventually led to large numbers of Goths and other Germanic peoples living within the Roman Empire becoming Christians. As it turned out, these Germanic Christians were largely estranged from their fellow Roman and Greek Christians because the creed that Ulfilas taught them was not the Nicene Creed, but rather a creed that distinguished between the persons of the Trinity.
Christianity was spread by preaching and lifestyle evangelism in the early days of the that faith. The roads that Romans had built made travel easy, safe, and convenient.
Christianity is based on the life, actions, and teachings of Jesus of Nazarth. He and his early followers lived in the Roman territory of Judea in southwest Asia. They spread Jesus' teachings to many people in Jerusalem and other cities in Judea.
The message of Christianity was spread around the Roman Empire by St. Paul who founded Christian churches in Asia Minor and Greece. Eventually, he took his teachings to Rome itself. The early converts to Christianity in Ancient Rome faced many difficulties. The first converts were usually the poor and slaves as they had a great deal to gain from the Christians being successful. If they were caught, they faced death for failing to worship the emperor. It was not uncommon for emperors to turn the people against the Christians when Rome was faced with difficulties. In AD 64, part of Rome was burned down. The Emperor Nero blamed the Christians and the people turned on them. Arrests and executions followed.
Christianity was adopted as the official state religion of the Roman Empire, the Empire itself spread Christianity.
Christianity spread throughout the Roman Empire primarily through Saul of Tarsus, also called Paul. Paul went to the Jewish Synagogues in each town he visited. There were both Jews and non-Jews that would attend though the latter were not officially part of Judaism. Paul would teach a few and set up a church and move on. Leaders were non-Jews who studied Judaism prior to conversion or converted Jews. Despite intense persecution, those committed were not swayed. In fact many direct attempts to persecution the church resulted in further expansion.
Latter in history, Constantine was fighting for the Empire. He supposedly saw a cross and was told conquer in this name. He did win and decided to make Christianity the religion of the Empire. From here on out Christianity became the "norm" instead of the outside religion.

Christianity began with Jewish followers of Jesus of Nazareth. They believed that Jesus of Nazareth was the "Christ," the savior that the Jewish prophecies said would come to Earth. Jesus taught that everyone must turn away from doing wrong things and start doing things that are pleasing to God. Jesus also taught his followers that they should spread this teaching to everyone they meet.
Under the leadership of the Apostles Peter and Paul, Christianity gradually separated from Judaism. Paul mainly preached to the Gentiles, the people who were not Jews. He taught that the God of Abraham is for all people, both Jews and Gentiles, instead of for Jews only. Christians were persecuted by the Roman Empire, as a part of the persecution of Jews. In 64 A.D., Nero blamed Christians for the great fire that broke out in Rome. Many forms of execution were used, including murder, crucifixion, and feeding of Christians to lions and other wild beasts. Christianity continued to spread throughout the Roman Empire, as Christians tried to move farther from Rome to spread their beliefs and escape death in Rome. It became an officially supported religion under Constantine I. All religions except Christianity were prohibited in 391 A.D.

A:

By the sword.

 

B:

Christianity spread throughout the Roman Empire in a series of steps.

We can start with the Day of Pentecost, the very first day of the Church, when Peter declared to the thousands gathered in Jerusalem for that festival that salvation, leading to eternal life, was available to all who repented of their sins and were baptised in the name of Jesus Christ. He told them that this promise was available to everyone, whether they were present that day, or in that place, or were far off in time or place. Three thousand became Christians on that day. They were drawn from a crowd of people who came from all over the Roman Empire, and from the Parthian (Persian) Empire as well.

A few years later, most of the early Christians fled from Jerusalem, since the authorities there were offended by the preaching of one of the Christian leaders, Stephen. One of the destinations of the fleeing Christians was the Syrian city of Antioch. It was in Antioch that Christianity began to be actively preached to non-Jews. This eventually led to the first organized missionary journey, conducted by Barnabas and Paul, and saw the Christian message go to Cyprus and then to southern Galatia, in Anatolia (modern Turkey). New churches were established in both regions. Further missionary journeys, by Paul and Silas, saw Christianity being spread in Greece and in the Roman province of Asia (also in Anatolia). Other missionaries took the Christian message to other places, such as Bithynia, Pontus and Cappadocia (also all in Anatolia), and individual Christians certainly took the Christian message to Rome.

So, within a generation of the Church starting, Christianity had already gained a foothold in many provinces of the Roman Empire, and certainly in all the provinces of the eastern half of the Roman Empire.

The next two hundred years saw the Christian Church expand and grow from these early roots. We have very little information about how this happened, but we have a few precious fragments, such as the account of the persecution of Christians in two cities on the Rhone river (in modern France). This is discussed in the related question, shown below, "What caused the spread of Christianity to go north of the alps?"

In Bithynia (in north-western Anatolia), at the beginning of the second century, the Roman governor, Pliny, discovered that the old cults were being deserted, and Christianity was widespread amongst the ordinary people. He claimed he had been able to suppress the Christian cult, and to encourage the people to return to the old cults, through a widespread policy of torture and execution of those most intractable followers of the Christian religion. Emperor Trajan supported his actions, but warned against a policy of seeking out Christians too vigorously.

Meanwhile, supporters of the traditional religions, and particularly the philosophers, were becoming aware of the challenge posed by Christianity. They met it in various ways. The best known of these responses is the work, The True Word, written by a Platonic philosopher in the middle of the second century, and embedded in a rebuttal written by the Christian philosopher, Origen, in the middle of the third century.

Origen's influence is rather difficult to assess, however, it appears that most of the bishops of the provincial capitals in Anatolia in the second half of the third century were influenced by his writing and teaching.

We know less than we would like to know about Christianity in the second half of the third century. Yet we can discern that the influence of Origen's teaching probably saw Christianity gaining intellectual ascendancy in Greece, Anatolia and Syria / Palestine. It was also gaining a measure of popular support in those places as well as in Egypt.

This period was bracketed by the two great periods of persecution in the history of the Church. The first was launched by Emperor Decius in 250, and tried again by Emperor Valerian in 257. The second was launched by Emperor Diocletian in 303. It is difficult to avoid the conclusion that the Church in the eastern half of the Roman Empire grew enormously between these two horrendous events.

In the western half of the Roman Empire, the Church was also growing, but it does not appear to have reached anywhere near the strength and importance of the Church in the eastern half of the Roman Empire. However, Constantine's conversion to Christianity, which can be reasonably dated to 312, changed everything, with the Christianity's status in the western half of the Empire being changed from a mostly tolerated religion, and sometime persecuted religion, to a favoured religion.

In 313, the emperor in the eastern half of the Roman Empire, Licinius, joined with Constantine in publishing the Edict of Milan, which granted Christianity formal tolerance throughout the Roman Empire. These colleagues in the Empire were also rivals, and in 324 Constantine defeated Licinius, and began to rule the entire Roman Empire on his own. Christianity was then favoured throughout the whole of the Roman Empire, in both the west and the east.

Christianity was already on the move before Constantine took power; now with state support it grew from strength to strength. The great Christian historian, Eusebius, admitted that he believed that many conversions to Christianity were for the wrong reasons. On the other hand, we have sufficient evidence to show that the free spread of Christianity resulted in many genuine conversions, and more significantly for this topic, the gradual phasing out of the old cults as a central part of the people's lives, with the notable exception of Rome itself.

There is no doubt that a measure of self-interest was involved in some conversions to Christianity. One can understand that this could initially have applied particularly to the curial class. These were the rich people who were required to fund basically all the civil functions of the state, and kept the cities operating. Initially, it was a simple change, since those members of the curial class who became Christian priests were no longer required to meet these obligations. This followed the previous practice of extending exemptions to those members of the curial class who took on other civic obligations, such as being priests of the traditional cults, taking responsibilities in the military, or becoming a senator. However, it was not really equivalent since being a Christian priest did not require the office holder to be engaged in truly overwhelmingly expensive tasks. As a result, in 329, Constantine required bishops and clergy to be generous towards the poor, thus officially requiring the Church to be involved in the charity work of the Empire, a task to which it was already heavily committed. Constantine also restricted the entry of the curial class into the priesthood.

Missionary activities within the Roman Empire continued during the fourth century, with most significant of these being the mission of Ulfilas to the Goths on the borders of the Roman Empire, which eventually led to large numbers of Goths and other Germanic peoples living within the Roman Empire becoming Christians. As it turned out, these Germanic Christians were largely estranged from their fellow Roman and Greek Christians because the creed that Ulfilas taught them was not the Nicene Creed, but rather a creed that distinguished between the persons of the Trinity.

Saint Paul is credited with spreading the Christian faith among the Gentiles - the non-Jewish population of the Empire. Expansion of the Christian faith was slow at first, but Christianity often appealed to poor people who felt alienated by mainstream religions.

By the beginning of the 4th century CE, Christianity is believed to have converted about ten percent of the population of the Roman Empire. Scholars believe that at this stage Christianity was evenly split between the proto-Catholic-Orthodox faith and Gnostic Christianity.

In the early 4th century, Emperor Constantine gave Christianity state patronage, after which the faith began to expand rapidly, as many felt that it was socially or politically desirable to embrace Christianity. Emperor Theodosius I made Christianity the official state religion of Rome in the 380s, and banned worship at pagan temples in 391. The spread of Christianity was soon complete.


See also the related question, shown below, "How did Christianity spread throughout the roman empire?"
through people like Paul and other believer's in the early church
Paul made 3 missionary journeys telling people about Jesus and how he died for us. People then told others and God moved in people
how did Christianity spread within the roman empire
Christianity did not spread to the Roman Empire. It started in the Roman Empire and spread from there.
because of its appeal to the lower class citizens of rome (heaven). 96% of rome was lower class after the pax romana
Emperor Constantine decided to adopt it when he thought that a Christian symbol (a cross) had brought him victory in battle. He made it legal and he even accepted baptism before his death, without banning the rest of the gods. After his death, the Church was quickly organised as a state institution, starting to push back, then fight, then ban all other religions.
Christianity spread within and throughout the Roman Empire when Emperor Constantine I claimed that he had seen the vision of a cross in the heavens, just before the Battle of Milvian Bridge in 312. Constantine explained that he had heard the words "En toutos Nika" (in Greek) or "In hoc signo vincis" (Latin).
  1. Evangelism
  2. State patronage, beginning with Emperor Constantine
  3. Persecution of the pagan temples
  4. Imperial dictate, beginning with Emperor Theodosius