The most important thing about Agabus is that he is a prophet who lived in Jerusalem.  He came to Antioch with a group of prophets.  Guided by the Holy Spirit he stood up and predicted that there would be a severe famine that would spread over the entire Roman world.  Luke, the writer of Acts, adds in parenthesis, that the famine did happen during the reign of Claudius.

I did some research and found that some ancient writers, Tacitus, Josephus and Suetonius, made reference to some great famines in Israel, about AD 45-46, which reached beyond Palestine.  These took place during the time of Claudius Caesar’s reign as Emperor of Rome. 

The fact that Agabus’s prediction came true authenticated his gift of prophecy.  God used his prediction to help the church in Jerusalem prepare for the famine by putting a burden on the hearts of believers in Antioch to provide help.  Once they gathered their gift they sent it to the elders in Jerusalem by Barnabas and Saul. 

It’s possible Paul had an ongoing burden to help in this way by taking up a collection years later on his third missionary trip, from the churches established during his first two mission trips. 

We see how authentic ministry by one Christian can have a long term impact on many believers.  It’s a Biblical example of how God mobilizes His church to meet the needs of His people.