There were different types of celebrities in the ancient world, just like there are today. Today actors and musicians are in the top tier of the celebrity world while war heroes are almost non-existent. Politicians are up there while poets have a very limited following.
In the ancient Roman world politicians and generals were on the top as were philosophers and poets. This hierarchy of the celebrity world exposes the core values of a society. The ancients valued cunning in battle, winning victories, and conquering. They also placed a high value on knowledge and learning among the elite.
When Paul wrote his letters, only a few years after Jesus had been crucified, the people in his churches had their own celebrities that they clamored to. Some of them had probably had gone to the arena and seen gladiators who held a certain amount of popularity. Some had listened to local or international philosophers and pondered on what they said, admiring their knowledge and intimidated by their celebrity like popularity.
Paul came into their cities and stirred up things, becoming somewhat of a celebrity as well. His name grew around the regions of the Mediterranean and people went to hear what all the buzz was about. In short, Paul had become somewhat of a celebrity with a fair share of people who became his followers - some who became avid fans.
But his popularity was constantly under attack intentionally or unintentionally by others. Peter, John, Apollos were some of those who stepped into Paul's territory without meaning any harm to him or to his ministry. Following Paul and moving into the same cities in which he ministered, these three and others won the hearts of many of Paul's followers.
Apollos was an amazing speaker that won over the hearts of those who were seduced by image and charisma. Peter and John gained celebrity status reputation by being the flesh and blood disciples of Jesus who had become the center of the Christian faith.
Other preachers moved into Paul's territory with intentions of taking Paul's followers away from him. Most of them believed they were doing service to God. Among them were Jewish Christians who hoped to instruct the Gentile Christians in the Law of Moses, thus leading them to a "deeper and better" walk with Christ. Others had secret and special revelations they wanted to pass on the the new Christians in Paul's churches. Some used their preaching to gain access into villages and homes of Paul's followers so that they could live off other peoples' kindness and generosity.
Every one of these types of people came into Paul's ministry and knowingly or unknowingly set themselves up as his competition.
Paul dealt with each of these in different ways - some of which is very surprising.
