The message spread through people and it spread because that is what Jesus told people to do:
Matthew 28:19 Go therefore and make disciples of all the nations, baptizing them in the name of the Father and of the Son and of the Holy Spirit,
On the day of Pentecost Peter preached the gospel message to people who were gathered in Jerusalem. (see Acts chapter 2 )
These people were Jews and Jewish converts from all over the known world. Many believed the gospel message and became Christians. When they went back to their home countries no doubt they told others, and so the message of salvation through Jesus Christ was spread.
The apostle Paul spread Christianity throughout the Mediterranean regionSaint Patrick spread Christianity throughout Ireland!
He is not responsible for either.
Many cultures are responsible for the spreading of Christianity. The main culture which spread it was certainly the Roman Empire.
Monks and missionaries
Paul is probably responsible for the spread of Christianity, after Jesus himself, of course. But without Paul or someone like him, Christianity may have remained an obscure cult of Judaism.
Christianity is spread all over the world.
By 325ad Christianity had spread throughout the Roman Empire and to Britain. If you google "spread of Christianity map" you will find maps showing the spread.
St. Paul traveled to spread the teachings of Christianity and to attract converts.St. Paul traveled to spread the teachings of Christianity and to attract converts.St. Paul traveled to spread the teachings of Christianity and to attract converts.St. Paul traveled to spread the teachings of Christianity and to attract converts.St. Paul traveled to spread the teachings of Christianity and to attract converts.St. Paul traveled to spread the teachings of Christianity and to attract converts.St. Paul traveled to spread the teachings of Christianity and to attract converts.St. Paul traveled to spread the teachings of Christianity and to attract converts.St. Paul traveled to spread the teachings of Christianity and to attract converts.
Kings and Monasteries helped to spread Christianity.
Monks help spread Christianity across Europe.
The spread of Christianity matters because it was one of the factors that shaped our western culture.The spread of Christianity matters because it was one of the factors that shaped our western culture.The spread of Christianity matters because it was one of the factors that shaped our western culture.The spread of Christianity matters because it was one of the factors that shaped our western culture.The spread of Christianity matters because it was one of the factors that shaped our western culture.The spread of Christianity matters because it was one of the factors that shaped our western culture.The spread of Christianity matters because it was one of the factors that shaped our western culture.The spread of Christianity matters because it was one of the factors that shaped our western culture.The spread of Christianity matters because it was one of the factors that shaped our western culture.
Saul spread Christianity