Now, Debbie Hunn has shown that the conventional assumptions about Gal 1-2 are wrong, and that there is therefore no reason to reject the famine visit. She writes,
Paul argues that he received the gospel from God by showing that he did not learn it from the apostles. Therefore, his evidence must include a record of any visit to Jerusalem. But when Paul adduced witnesses to the fact that he was preaching the gospel to Gentiles while unknown by sight in Judea in 1,22-24, he finished his proof that he had not gone to the apostles for his message.While Paul argues in Gal 1:16-24 that he had preached his gospel before he had had much contact the Judean church, he does not do the same thereafter. In Gal 2:1-10 Paul does not say that he did not meet many believers in Jerusalem, and nor does he say that he spent little time there. In Gal 2:1-10 Paul provides different arguments to show that his motive for preaching Gentile liberty was not to ingratiate himself with the Jerusalem church leaders.
Many assume that Paul mentioned the interval of 14 years (Gal 2:1) to show that there was a long interval before he returned to Jerusalem. However, Paul is arguing that he did not preach Gentile liberty out of a desire to please the Jerusalem church, so he mentions the 14 years to show that it was a long time before he bothered to ascertain the Jerusalem church's position on the issue. This says nothing about whether he had made a visit to Jerusalem in the interval.
If Paul really had not been back to Jerusalem until the visit of Gal 2:1-10, as many suppose, he surely would have said so to strengthen his case. Surely he would have written something like, "When I departed for Jerusalem 14 years later, I was still unknown by face to the churches there". In fact Paul makes no claim about the duration of time in which he was unknown to the believers in Judea (Gal 1:22-24).
It seems to me that the name "Agabus" also supports the historicity of the famine visit. The name probably means, "Locust" and would therefore be a very appropriate nickname for this OT-style prophet who predicted the famine. Locust were associated with food shortages in OT prophecies (Exodus 10:4-19; Deut 28:38,42; 1 Kings 8:38; 2 Chron 7:13; Psalm 78:46; Psalm 105:34; Joel 1:4; 2:25; Amos 4:9; 7:1). Nicknames were quite common in Palestine at this time, perhaps because so many people had a name that was so common that an additional name was needed to distinguish them from others. Tal Ilan (Lexicon of Jewish Names in Late Antiquity part I Palestine 330 BCE-200CE) identifies 2826 people and 188 probable cases of nicknames (7%). The name "Agabus" is either unattested elsewhere or virtually so. For these reasons we should assume that "Agabus" was his nickname. Now, the name is Hebrew, so it is unlikely that Luke invented it. The historicity of Luke's account is therefore supported by the fact the the name "Agabus" is so appropriate for this predictor of famine.